MATTHEW, SUPPLEMENT ARY NOTE 13 



of transporting certain types of adult reptiles, amj)hibians or inverte- 

 brates in the particular way that I have nsecl to account for certain pecu- 

 liarities in mammalian distribution, yet the transport of their eggs is a 

 much less serious difficulty, and there are several other possible methods. 

 These have been extensively discussed by others and I need not go into 

 them. 'While it does not seem physically possible, for instance, that a 

 mammal could survive being caught up by a hurricane or tornado^ car- 

 ried a long distance and dropped, I do not see any particular impossi- 

 hility in the transport of young or eggs of amphibians or reptiles or in- 

 vertebrates by such means. Indeed there is considerable evidence along 

 this line on record. And if it be not a physical impossibility, then the 

 element of geologic time does enter into the question of its probability. 



So far as the West Indies are concerned, I do not at all suppose that no 

 one of them has ever been united to any other. All are in lines of great 

 disturbance and uplift; several are united by shallow platforms, and I 

 see no reason at all against accepting Yaughan's view that Cuba and 

 Haiti M'ere probably united during the Tertiary, although now separated 

 by a deep water channel. The mammalian evidence would accord well 

 with that view, and recent discoveries in Porto Eico rather suggest that 

 that island, as well as the Bahamas, may have been included in the union. 

 But the mammalian evidence seems to me distinctly against any direct 

 union with either Korth or South America in the middle or later Ter- 

 tiary, and fairly conclusive against any such Pleistocene union. Indirect 

 union, with an isolated Central American or Floridian island serves to 

 raise problems of dispersal more difficult than any that it solves, because 

 we have no past distributional evidence to go upon. It is too speculative 

 to be worth discussion. 



Dr. Barbour's criticisms deal, as he very cordially and generously in- 

 sists, with a side issue of the main discussion in my paper. I may add 

 that it is a side issue concerning which I have no desire to be dogmatic 

 or positive. 



My statement that the large ground birds are to-day peculiarly inhab- 

 itants of arid regions should have been more carefully qualified. It re- 

 ferred especially to the three large forms — ^the ostrich, Thea and emu — 

 characteristic of the arid interior of the three southern continents. I had 

 not meant to say that there was any such uniform association of habitat 

 as the remark may seem to imply. 



In reply to Doctor Allen's argument concerning Madagascar Cricetines, 

 the following points may be considered : 



1) All the Malagasy rodents belong to a peculiar group of Cricetines, 

 the ]Sresomyina> : tliat is to say, if the classification is a natural one they 



