Sixty years of Halffter’s Mexican Transition Zone: a systematic review using bibliometric tools
DOI:
https://doi.org/10.22201/ib.20078706e.2023.94.5114Keywords:
Halffter’s theory, Scientific impact, Bibliometric analysis, Content analysis, Patterns of distributionAbstract
The Mexican Transition Zone (MTZ) has become a key concept that has promoted the consolidation of an integrative field of research. We reviewed the scientific publications on the MTZ with bibliometric tools to detect trends through time and analyze the conceptual structure and historiographic citation. We also performed a content analysis considering the conceptualization of the MTZ, the application of Halffter’s patterns of distribution, and the different disciplines where the term has been used. The number of publications per year has not been constant, but since 2012 there has been a general increase, becoming the MTZ frequently cited in papers and in some cases constituting a research topic. We identified divergences in the conceptualization of the MTZ and discussed the implications for biogeographic studies. Halffter’s conceptualization of the Mexican Transition Zone has inspired other authors to produce research focused on this area and to set biogeographic hypotheses but also to redefine the concept and make it applicable through its incorporation in the biogeographical regionalization of the Americas.
References
Álvarez, F., Villalobos, J. L., Armendáriz, G., & Hernández, C. (2012). Biogeographic relationship of freshwater crabs and crayfish along the Mexican transition zone: Reevaluating Rodríguez (1986) hypothesis. Revista Mexicana de Biodiversidad, 83, 1073–1083. https://doi.org/10.7550/rmb.28230
Anguiano-Constante, M. A., Dean, E., Starbuck, T., Rodríguez, A., & Munguía-Lino, G. (2021). Diversity, species richness distribution and centers of endemism of Lycianthes (Capsiceae, Solanaceae) in Mexico. Phytotaxa, 514, 39–60. https://doi.org/10.11646/phytotaxa.514.1.3
Aria, M., & Cuccurullo, C. (2017). bibliometrix: An R-tool for comprehensive science mapping analysis. Journal of Informetrics, 11, 959–975. https://doi.org/10.1016/j.joi.2017.08.007
Arriaga-Jiménez, A., Rös, M., & Halffter, G. (2018). High variability of dung beetle diversity patterns at four mountains of the Trans-Mexican Volcanic Belt. PeerJ, 6, e4468. https://doi.org/10.7717/peerj.4468
Berniker, L., & Weirauch, C. (2012). New World biogeography and the evolution of polychromatism: evidence from the bee assassin genus Apiomerus (Heteroptera: Reduviidae: Harpactorinae). Systematic Entomology, 37, 32–54. https://doi.org/10.1111/j.1365-3113.2011.00600.x
Cabrero-Sañudo, F., Trotta-Moreu, N., & Morales, I. (2007). Phenology, reproductive cycles, and species composition of a dung beetle community (Coleoptera: Scabaeoidea) from a high mountain pasture system on the oriental Neovolcanic Axis (Veracruz, Mexico). Proceedings of the Entomological Society of Washington, 109, 813–828.
Campos-Soldini, M. P., García, M. S., & Safenraiter, M. E. (2015). Track analysis of the North, Central, and South American species of the Epicauta maculata group (Coleoptera: Meloidae). Neotropical Entomology, 44, 309–318. https://doi.org/10.1007/s13744-015-0287-4
Canales, G. M., & Goyenechea, I. (2022). Amphibian areas of endemism: a conservation priority in the threatened Mexican cloud forest. Vertebrate Zoology, 72, 235–244. https://doi.org/10.3897/vz.72.e73534
Cano, E. B., Schuster, J. C., & Morrone, J. J. (2018). Phylogenetics of Ogyges Kaup and the biogeography of Nuclear Central America (Coleoptera, Passalidae). Zookeys, 737, 81–111. https://doi.org/10.3897/zookeys.737.20741
Castro-Castro, A., Vargas-Amado, G., Castañeda-Nava, J. J., Harker, M., Munguía-Lino, G., Santacruz-Ruvalcaba, F. et al. (2017). Chromosomic numbers for three species of Cosmos section Discopoda (Asteraceae, Coreopsideae), with cytogeographic notes. Acta Botanica Mexicana, 41–51. https://doi.org/10.21829/abm118.2017.1199
Contreras-Medina, R., Vega, I. L., & Morrone, J. J. (2007). Gymnosperms and cladistic biogeography of the Mexican Transition Zone. Taxon, 56, 905–916. https://doi.org/10.2307/25065872
Corral-Rosas, V., & Morrone, J. J. (2016). Analysing the assembly of cenocrons in the Mexican transition zone through a time-sliced cladistic biogeographic analysis. Australian Systematic Botany, 29, 489–501. https://doi.org/10.1071/SB16048
Coulleri, J. P., & Ferrucci, M. S. (2012). Biogeografía histórica de Cardiospermum y Urvillea (Sapindaceae) en América: Paralelismos geográficos e históricos con los bosques secos estacionales neotropicales. Boletín de la Sociedad Argentina de Botánica, 47, 103–117.
Crisci, J. V., Katinas, L., & Posadas, P. (2003). Historical biogeography: an introduction. Cambridge: Harvard University Press.
Darlington, P. J. (1957). Zoogeography: the geographical distribution of animals. New York: Wiley.
Daza, J. M., Smith, E. N., Páez, V. P., & Parkinson, C. L. (2009). Complex evolution in the Neotropics: the origin and diversification of the widespread genus Leptodeira (Serpentes: Colubridae). Molecular Phylogenetics and Evolution, 53, 653–667. https://doi.org/10.1016/j.ympev.2009.07.022
De Mendonça, L. H., & Ebach, M. C. (2020). A review of transition zones in biogeographical classification. Biological Journal of the Linnean Society, 131, 717–736. https://doi.org/10.1093/biolinnean/blaa120
Escalante, T., Morrone, J. J., & Rodríguez-Tapia, G. (2013). Biogeographic regions of North American mammals based on endemism: biogeographical regionalization of North America. Biological Journal of the Linnean Society, 110, 485–499. https://doi.org/10.1111/bij.12142
Escalante, T., Noguera-Urbano, E. A., & Corona, W. (2018). Track analysis of the Nearctic region: identifying complex areas with mammals. Journal of Zoological Systematics and Evolutionary Research, 56, 466–477. https://doi.org/10.1111/jzs.12211
Escalante, T., Rodríguez, G., Cao, N., Ebach, M. C., & Morrone, J. J. (2007). Cladistic biogeographic analysis suggests an early Caribbean diversification in Mexico. Naturwissenschaften, 94, 561–565. https://doi.org/10.1007/s00114-007-0228-0
Escalante, T., Rodríguez, G., & Morrone, J. J. (2004). The diversification of Nearctic mammals in the Mexican transition zone. Biological Journal of the Linnean Society, 83, 327–339. https://doi.org/10.1111/j.1095-8312.2004.00386.x
Escalante, T., Rodríguez-Tapia, G., & Morrone, J. J. (2021). Toward a biogeographic regionalization of the Nearctic region: Area nomenclature and digital map. Zootaxa, 5027, 351–375. https://doi.org/10.11646/zootaxa.5027.3.3
Espinosa, D., Llorente, J., & Morrone, J. J. (2006). Historical biogeographical patterns of the species of Bursera (Burseraceae) and their taxonomic implications. Journal of Biogeography, 33, 1945–1958. https://doi.org/10.1111/j.1365-2699.2006.01566.x
Espinosa, D., Ocegueda, S., Flores, O., & Llorente, J. (2008). El conocimiento biogeográfico de las especies y su regionalización natural. In J. Sarukhán (Ed.), Capital Natural de México (pp. 33–65). Mexico City: Comisión Nacional para el conocimiento y uso de la Biodiversidad.
Falcón-Ordaz, J., Monks, S., Pulido-Flores, G., & Amador, R. (2014). A new species of Aplectana (Nematoda: Cosmocercidae) in Ambystoma velasci (Amphibia: Ambystomatidae) from Mexico. Comparative Parasitology, 81, 220–224. https://doi.org/10.1654/4684.1
Ferrari, A., Alvares, D. J., Buratto, P. M., & Barão, K. R. (2022). Distribution patterns of Triatominae (Hemiptera: Reduviidae) in the Americas: an analysis based on networks and endemicity. Cladistics, 38, 563–581. https://doi.org/10.1111/cla.12500
Ferro, I., Navarro-Sigüenza, A. G., & Morrone, J. J. (2017). Biogeographical transitions in the Sierra Madre Oriental, Mexico, shown by chorological and evolutionary biogeographical affinities of passerine birds (Aves: Passeriformes). Journal of Biogeography, 44, 2145–2160. https://doi.org/10.1111/jbi.13015
García‐Sotelo, U. A., García‐Vázquez, U. O., & Espinosa, D. (2021). Historical biogeography of the genus Rhadinaea (Squamata: Dipsadinae). Ecology and Evolution, 11, 12413–12428. https://doi.org/10.1002/ece3.7988
Gutiérrez-Ortega, J. S., Salinas-Rodríguez, M. M., Martínez, J. F., Molina-Freaner, F., Pérez-Farrera, M. A., Vovides, A. P. et al. (2018). The phylogeography of the cycad genus Dioon (Zamiaceae) clarifies its Cenozoic expansion and diversification in the Mexican transition zone. Annals of Botany, 121, 535–548. https://doi.org/10.1093/aob/mcx165
Gutiérrez-Rodríguez, J., Zaldívar-Riverón, A., Weissman, D. B., & Vandergast, A. G. (2022). Extensive species diversification and marked geographic phylogenetic structure in the Mesoamerican genus Stenopelmatus (Orthoptera: Stenopelmatidae: Stenopelmatinae) revealed by mitochondrial and nuclear 3RAD data. Invertebrate Systematics, 36, 1–21.
https://doi.org/10.1071/IS21022
Gutiérrez-Velázquez, A., Rojas-Soto, O., Reyes-Castillo, P., & Halffter, G. (2013). The classic theory of Mexican Transition Zone revisited: the distributional congruence patterns of Passalidae (Coleoptera). Invertebrate Systematics, 27, 282–293. https://doi.org/10.1071/IS12056
Halffter, G. (1962). Explicación preliminar de la distribución geográfica de los Scarabaeidae mexicanos. Acta Zoológica Mexicana, 5, 1–17.
Halffter, G. (1964). La entomofauna americana, ideas acerca de su origen y distribución. Folia Entomológica Mexicana, 6, 1–108.
Halffter, G. (1965). Algunas ideas acerca de la zoogeografía de América. Revista de la Sociedad Mexicana de Historia Natural, 26, 1–16.
Halffter, G. (1974). Éléments anciens de l’entomofaune neotropicale: Ses implications biogéographiques. Quaestiones Entomologicae, 10, 223–262.
Halffter, G. (1976). Distribución de los insectos en la Zona de Transición Mexicana: Relaciones con la entomofauna de Norteamérica. Folia Entomológica Mexicana, 35, 1–64.
Halffter, G. (1978). Un nuevo patrón de dispersión en la Zona de Transición Mexicana: el Mesomericano de Montaña. Folia Entomológica Mexicana, 39–40, 219–222.
Halffter, G. (1987). Biogeography of the montane entomofauna of Mexico and Central America. Annual Review of Entomology, 95–114.
Halffter, G. (2003). Biogeografía de la entomofauna de montaña de México y América Central. In: J. J. Morrone & J. Llorente-Bousquets (Eds.), Una perspectiva latinoamericana de la biogeografía (pp. 87–97). Mexico City: Las Prensas de Ciencias, UNAM.
Halffter, G. (2017). La zona de transición mexicana y la megadiversidad de México: Del marco histórico a la riqueza actual. Dugesiana, 24, 77–89. https://doi.org/10.32870/dugesiana.v24i2.6572
Halffter, G., & Morrone, J. J. (2017). An analytical review of Halffter’s Mexican transition zone, and its relevance for evolutionary biogeography, ecology and biogeographical regionalization. Zootaxa, 4226, 1–46. https://doi.org/10.11646/zootaxa.4226.1.1
Halffter, G., Zunino, M., Moctezuma, V., & Sánchez-Huerta, J. L. (2019). The integration processes of the distributional patterns in the Mexican Transition Zone: phyletic, paleogeographic and ecological factors of a case study. Zootaxa, 4586, 1–34. https://doi.org/10.11646/zootaxa.4586.1.1
Joaqui, T., Cultid‐Medina, C. A., Dáttilo, W., & Escobar, F. (2021). Different dung beetle diversity patterns emerge from overlapping biotas in a large mountain range of the Mexican Transition Zone. Journal of Biogeography, 48, 1284–1295. https://doi.org/10.1111/jbi.14075
Joaqui, T., Moctezuma, V., Sánchez-Huerta, J. L., & Escobar, F. (2019). The Onthophagus fuscus (Coleoptera: Scarabaeidae) species complex: an update and the description of a new species. Zootaxa, 4555, 151. https://doi.org/10.11646/zootaxa.4555.2.1
Juárez-Barrera, F., Espinosa, D., Morrone, J. J., Escalante, T., & Bueno-Hernández, A. A. (2020). La complejidad biótica de la Zona de Transición Mexicana y la evolución del pensamiento biogeográfico de Gonzalo Halffter. Revista Mexicana de Biodiversidad, 91, e913402. https://doi.org/10.22201/ib.20078706e.2020.91.3402
Lamas, C. J. E., Nihei, S. S., Cunha, A. M., & Couri, M. S. (2014). Phylogeny and biogeography of Heterostylum (Diptera: Bombyliidae): Evidence for an ancient Caribbean diversification model. Florida Entomologist, 97, 952–966. https://doi.org/10.1653/024.097.0353
López-García, M. M., & Morrone, J. J. (2022). Geodispersal of the Typical Neotropical cenocron from South America to the Mexican Transition Zone: A cladistic biogeographical test. Biological Journal of the Linnean Society, 135, 242–250. https://doi.org/10.1093/biolinnean/blab161
Martín-Piera, F., & Lobo, J. M. (1993). Altitudinal distribution patterns of copro-necrophage Scarabaeoidea (Coleoptera) in Veracruz, México. The Coleopterists Bulletin, 47, 321–334.
Mason, N. A., Olvera-Vital, A., Lovette, I. J., & Navarro-Sigüenza, A. G. (2018). Hidden endemism, deep polyphyly, and repeated dispersal across the Isthmus of Tehuantepec: diversification of the White-collared seedeater complex (Thraupidae: Sporophila torqueola). Ecology and Evolution, 8, 1867–1881. https://doi.org/10.1002/ece3.3799
Moctezuma, V., Deloya, C., Sánchez-Huerta, J. L., & Halffter, G. (2019). A new species of the Phanaeus endymion species group (Coleoptera: Scarabaeidae: Scarabaeinae), with comments on ecology and distribution. Annales de la Société Entomologique de France (N.S.), 55, 249–254. https://doi.org/10.1080/00379271.2019.1577170
Moctezuma, V., & Halffter, G. (2019). New biogeographical makeup for colonisation of the Baja California Peninsula, with the description of a new Onthophagus (Coleoptera: Scarabaeidae: Scarabaeinae). Journal of Natural History, 53, 2057–2071. https://doi.org/10.1080/00222933.2019.1685694
Moctezuma, V., Rossini, M., Zunino, M., & Halffter, G. (2016). A contribution to the knowledge of the mountain entomofauna of Mexico with a description of two new species of Onthophagus Latreille, 1802 (Coleoptera, Scarabaeidae, Scarabaeinae). Zookeys, 572, 23–50. https://doi.org/10.3897/zookeys.572.6763
Moctezuma, V., Sánchez-Huerta, J. L., & Halffter, G. (2018). Two new species of Ateuchus with remarks on ecology, distributions, and evolutionary relationships (Coleoptera, Scarabaeidae, Scarabaeinae). Zookeys, 747, 71–86. https://doi.org/10.3897/zookeys.747.22731
Morrone, J. J. (2004). Panbiogeografía, componentes bióticos y zonas de transición. Revista Brasileira de Entomologia, 48, 149–162. https://doi.org/10.1590/S0085-56262004000200001
Morrone, J. J. (2005). Hacia una síntesis biogeográfica de México. Revista Mexicana de Biodiversidad, 76, 207–252. https://doi.org/10.22201/ib.20078706e.2005.002.303
Morrone, J. J. (2006). Biogeographic areas and transition zones of Latin America and the Caribbean Islands based on panbiogeographic and cladistic analyses of the entomofauna. Annual Review of Entomology, 51, 467–494. https://doi.org/10.1146/annurev.ento.50.071803.130447
Morrone, J. J. (2010). Fundamental biogeographic patterns across the Mexican Transition Zone: An evolutionary approach. Ecography, 33, 355–361. https://doi.org/10.1111/j.1600-0587.2010.06266.x
Morrone, J.J. (2014). Biogeographical regionalisation of the Neotropical region. Zootaxa, 3782, 1–110. https://doi.org/10.11646/zootaxa.3782.1.1
Morrone, J. J. (2015). Halffter’s Mexican transition zone (1962-2014), cenocrons and evolutionary biogeography. Journal of Zoological Systematics and Evolutionary Research, 53, 249–257. https://doi.org/10.1111/jzs.12098
Morrone, J. J. (2017). Biogeographic regionalization of the Sierra Madre del Sur province, Mexico. Revista Mexicana de Biodiversidad, 88, 710–714. https://doi.org/10.1016/j.rmb.2017.07.012
Morrone, J. J. (2019). Regionalización biogeográfica y evolución biótica de México: Encrucijada de la biodiversidad del Nuevo Mundo. Revista Mexicana de Biodiversidad, 90, e902980. https://doi.org/10.22201/ib.20078706e.2019.90.2980
Morrone, J. J. (2020). The Mexican Transition Zone: a natural biogeographic laboratory to study biotic assembly. Cham: Springer International Publishing.
Morrone, J. J., & Ebach, M. C. (2022). Toward a terrestrial biogeographical regionalisation of the world: Historical notes, characterisation and area nomenclature. Australian Systematic Botany, 35, 187-224. https://doi.org/10.1071/SB22002
Morrone, J. J., Escalante, T., Rodríguez-Tapia, G., Carmona, A., Arana, M., & Mercado-Gómez, J. D. (2022). Biogeographic regionalization of the Neotropical region: New map and shapefile. Anais da Academia Brasileira de Ciências, 94, e20211167. https://doi.org/10.1590/0001-3765202220211167
Morrone, J. J., & Guerrero, J. C. (2008). General trends in world biogeographic literature: A preliminary bibliometric analysis. Revista Brasileira de Entomologia, 52, 493–499. https://doi.org/10.1590/S0085-56262008000400002
Morrone, J. J., & Márquez, J. (2001). Halffter’s Mexican Transition Zone, beetle generalized tracks, and geographical homology. Journal of Biogeography, 28, 635–650.
Nolasco-Soto, J., Favila, M. E., Espinosa-de los Monteros, A., González-Astorga, J., Halffter, G., Valdez-Carrasco, J. et al. (2020). Variations in genetic structure and male genitalia suggest recent lineage diversification in the Neotropical dung beetle complex Canthon cyanellus (Scarabaeidae: Scarabaeinae). Biological Journal of the Linnean Society, 131, 505–520. https://doi.org/10.1093/biolinnean/blaa131
Nolasco-Soto, J., González-Astorga, J., Espinosa-de los Monteros, A., Galante-Patiño, E., & Favila, M. E. (2017). Phylogeographic structure of Canthon cyanellus (Coleoptera: Scarabaeidae), a Neotropical ding beetle in the Mexican Transition Zone: insights on its origin and the impacts of Pleistocene climatic fluctuations on population dynamics. Molecular Phylogenetics and Evolution, 109, 180–190. https://doi.org/10.1016/j.ympev.2017.01.004
Ortiz-Brunel, J. P., Munguía-Lino, G., Castro-Castro, A., & Rodríguez, A. (2021). Biogeographic analysis of the American genus Echeandia (Agavoideae: Asparagaceae). Revista Mexicana de Biodiversidad, 92, e923739. https://doi.org/10.22201/ib.20078706e.2021.92.3739
Pérez-Hernández, C. X., Zaragoza-Caballero, S., & Romo-Galicia, A. (2022). Updated checklist of the fireflies (Coleoptera: Lampyridae) of Mexico. Zootaxa, 5092, 291–317. https://doi.org/10.11646/zootaxa.5092.3.3
Pérez-Miranda, F., Mejía, O., López, B., & Říčan, O. (2020). Molecular clocks, biogeography and species diversity in Herichthys with evaluation of the role of Punta del Morro as a vicariant brake along the Mexican Transition Zone in the context of local and global time frame of cichlid diversification. PeerJ, 8, e8818. https://doi.org/10.7717/peerj.8818
Phillips-Rodríguez, E., & Powell, J. A. (2007). Phylogenetic relationships, systematics, and biology of the species of Amorbia Clemens (Lepidoptera: Tortricidae: Sparganothini). Zootaxa, 1670, 1–109. https://doi.org/10.11646/zootaxa.1670.1.1
Pinedo‐Escatel, J. A., Aragón‐Parada, J., Dietrich, C. H., Moya‐Raygoza, G., Zahniser, J. N., & Portillo, L. (2021). Biogeographical evaluation and conservation assessment of arboreal leafhoppers in the Mexican Transition Zone biodiversity hotspot. Diversity and Distributions, 27, 1051–1065. https://doi.org/10.1111/ddi.13254
Pinilla-Buitrago, G. E., Escalante, T., Gutiérrez-Velázquez, A., Reyes-Castillo, P., & Rojas-Soto, O. R. (2018). Areas of endemism persist through time: A palaeoclimatic analysis in the Mexican Transition Zone. Journal of Biogeography, 45, 952–961. https://doi.org/10.1111/jbi.13172
Posadas, P., & Donato, M. (2007). Everything you always wanted to know about historical biogeography, but were afraid to ask: a preliminary overview based on papers published in Journal of Biogeography 2005-2006. Biogeografía, 2, 1–6.
Reyes-Castillo, P. (2003). Las ideas biogeográficas de Gonzalo Halffter: importancia e impacto. In J. J. Morrone, & J. Llorente-Bousquets (Eds.), Una perspectiva latinoamericana de la biogeografía (pp. 99–108). Mexico City: Las Prensas de Ciencias, UNAM.
Rosas, M. V., Guadalupe-del Río, M., Lanteri, A. A., & Morrone, J. J. (2011). Track analysis of the North and Central American species of the Pantomorus-Naupactus complex (Coleoptera: Curculionidae). Journal of Zoological Systematics and Evolutionary Research, 49, 309–314. https://doi.org/10.1111/j.1439-0469.2011.00631.x
Rossini, M., Vaz-de Mello, F. Z., & Zunino, M. (2018). A taxonomic revision of the New World Onthophagus Latreille, 1802 (Coleoptera: Scarabaeidae: Scarabaeinae) of the osculatii species-complex, with description of two new species from South America. Journal of Natural History, 52, 541–586. https://doi.org/10.1080/00222933.2018.1437230
Salomão, R. P., Arriaga-Jiménez, A., & Kohlmann, B. (2021). The relationship between altitudinal gradients, diversity, and body size in a dung beetle (Coleoptera: Scarabaeinae: Onthophagus) model system. Canadian Journal of Zoology, 99, 33–43. https://doi.org/10.1139/cjz-2020-0072
Sánchez-Chávez, E., Rodríguez, A., Castro-Castro, A., Pérez-Farrera, M. A., & Sosa, V. (2019). Spatio-temporal evolution of climbing habit in the Dahlia-Hidalgoa group (Coreopsidae, Asteraceae). Molecular Phylogenetics and Evolution, 135, 166–176. https://doi.org/10.1016/j.ympev.2019.03.012
Schramm, F. D., Valdez‐Mondragón, A., & Prendini, L. (2021). Volcanism and palaeoclimate change drive diversification of the world’s largest whip spider (Amblypygi). Molecular Ecology, 30, 2872–2890. https://doi.org/10.1111/mec.15924
Siddaway, A. P., Wood, A. M., & Hedges, L. V. (2019). How to do a systematic review: a best practice guide for conducting and reporting narrative reviews, meta-analyses, and meta-syntheses. Annual Review of Psychology, 70, 747–770. https://doi.org/10.1146/annurev-psych-010418-102803
Villaseñor, J. L., Ortiz, E., Delgadillo-Moya, C., & Juárez, D. (2020). The breadth of the Mexican Transition Zone as defined by its flowering plant generic flora. Plos One, 15, e0235267. https://doi.org/10.1371/journal.pone.0235267
Waldren, G. C., Williams, K. A., Cambra, R. A., & Pitts, J. P. (2020). Systematic revision of the North American velvet ant genus Invreiella Suárez (Hymenoptera: Mutillidae) with description of eleven new species. Zootaxa, 4894, 151–205. https://doi.org/10.11646/zootaxa.4894.2.1
Wallace, A. R. (1876). The geographical distribution of animals, with a study of the relations of living and extinct faunas as elucidating the past changes of the earth’s surface. London: MacMillan and Co.