22 Hans Gadow, 



but more probaby from the South, its nearest relations liviiig now in 

 Aiistralia. Exactl}^ the reverse applies to CoroneUa, which genus, 

 in the wider sense, comprises about six species in Eiirope, North 

 and West Africa, one in the cid Deccan, and the rest, about ten 

 species with endless varieties in North America, whence only a few 

 have extended into Mexico, and C. microphoh's alone to the Equator. 

 So far as America is concerned, Coronella is a Nearctic, Elaps a 

 Neotropical genus, each having- sent a few species into Mexico, that 

 interesting meeting ground of the faunas and floras of the Northern 

 and of the Southern World. 



But why, it will be asked, is America füll of this Elapoid 

 coloration, which is so rare in Indo-Malaya, and practically absent 

 elsewhere ? Because the America environment favours the production 

 of red in snakes. There would be plenty of harmless Coralsnakes 

 although Elaps had never found its way into the New World, and 

 the many sorts of Elaps would be just as pretty as they are now, 

 if there were none to copy them. 



Tropical American forests are inhabited by a surprising number 

 of animals with prehensile tails, Marsupiais, Edentates, Eodents, 

 Insectivores , Carnivores and Monkeys. In the equally luxuriant 

 tropical forests of the Old World this effective principle is unknown 

 amongst mammals. Why? Or why not? A Mexican Indian's answer 

 would be ,,no es costumbre", it is not the fashion; the Scientist 

 appeals to environment and natural selection, and means, but does 

 not like to say: Genius loci. 



November 2nd 1910. 



