196 R. D. Oldham— ^ome Bough Notes for the [No. 3, 



impossible to grant,* and I am ready to admit that the facts of distri- 

 bution of animals as detailed by him are conclusive against the possibi- 

 lity of such a distribution of land and water, at any rate since the Miocene 

 period. But there is no reason to suppose that the present distribution of 

 plants or animals can throw any light on the distribution of land and water 

 in late Palaeozoic and early Secondary times. On the other hand, in favour 

 of the land connection, I claim, firsthj, that the relationship between the 

 fauna and flora of the Damudas on the one hand and the Karoo beds on 

 the other is far more real and close than the mere ' similarity of animal and 

 vegetable productions ' to which Mr. Wallace seems to have considered 

 it to be confined ; secondly, that this relationship of the two floras con- 

 tinued into the Uitenhage and Eajmahal series, which could hardly have 

 been the case had the two areas been as separated then as now ; and, 

 thirdhj, that the very peculiar relationships and differences between the 

 cretaceous faunas of Central and Southern India on the one hand and 

 Arabia and South Africa on the other are such as imperatively to de- 

 mand the existence of a continuous barrier of dry land stretching be- 

 tween India and Africa. It is needless to expatiate further on this point, 

 for, if such a barrier existed during the Cretaceous period, any argument 

 against its possibility derived from the doctrine of the permanence of 

 continents must fall to the ground, and there remains no reason why, if 

 on independant grounds its existence is shewn to be probable, such a 

 modification as I require may not have existed at the commencement of 

 the Secondary period. That, during the deposition of the Damudas, there 

 was continuous land communication with South Africa I do not suppose, 

 for the very remarkable reptilian fauna, which, like the recent marsupial 

 fauna of Australia, mimicked many of the higher mammalia, points 

 rather to some isolated continental island which was connected with 

 India, as Australia now is with Asia, by a chain of large islands separated 

 by narrow straits, across which the spores of ferns and the seeds of 

 plants could be wafted, but which were impassable to terrestrial reptiles. 

 But even a land connection of this sort would probably be inade- 

 quate by itself to account for the close relationship which the small frag- 

 ment preserved to us of the flora of the Uitenhage period shews to that of 

 the Bajmahals. For it is at least highly probable that the heat of the 

 Equator would be as effectual a barrier as a broad sea, and, if the floras of 

 India and Africa had pursued independent courses of development for a 

 period sufficient for the dying out of every species and almost every 

 genus, and for a change in the facies of the flora from one composed 

 mainly of ferns to one composed mainly of cycads, it is inconceivable that 

 the floras of the Uitenhage and Rajmahal series should exhibit the close 



* Island Life, p. 398. 



