RECENT SCIENCE. 823 



persistence of the chief outlines of the continents seems to be 

 opposed to the admission. Dr. Ihering, who has devoted a good 

 deal of time to the study of the fauna of South America, boldly 

 concludes from his own special researches that during the Sec- 

 ondary period a great continent extended from Chili and Pata- 

 gonia, through New Zealand, to Australia, while the connection 

 between South America and North America was broken during 

 both the Cretaceous period and a great part of the Tertiary 

 epoch. The striking differences between the faunas of both 

 Americas, and the identity of many representatives of the fau- 

 nas of South America and South Africa, make him also conclude 

 that the two latter continents were connected as late as the Oligo- 

 cene period.* R. Lydekker, whose opinion has such a weight in 

 the matter, also concludes from the many known affinities be- 

 tween the fossil faunas and floras of the four great southern pro- 

 longations of the continental mass of the globe that they must 

 have stood in a more or less intimate connection, and have been 

 partially isolated from the more northern lands, f As to F. 

 Ameghino, he also recognizes that, at least during the Oligocene 

 times, South America was in direct connection with the Old 

 World ; but he points out the similarity of the mammalian and 

 Dinosaurian faunas of both Americas, and concludes that the 

 two continents must have been connected, as well as North 

 America with Europe, at an earlier epoch. 



It would be premature to attempt now the solution of this 

 complicated question. It may be permitted, however, to point 

 out that the hypothesis of a submerged antarctic continent is not 

 improbable from the point of view of the physical geographer. 

 The permanence of the continents, which is a fact, and seems to 

 be opposed to the hypothesis, must be understood in a limited 

 sense. In the equatorial and the two temperate zones we un- 

 doubtedly have huge continental masses, the great plateaus of 

 Asia, both Americas, and Africa, which, so far as our knowledge 

 goes, have not been submerged since the primary epoch; and 

 around these backbones of the continents we have huge masses 

 of land which have not been under the sea since the end of the 

 Secondary period. But their outskirts have witnessed several 

 retreats and invasions of the ocean, or of its Secondary period 

 seas. Moreover, the permanence of the continents does not seem 

 to extend to the circumpolar zones. When we consider the out- 

 lines of the two great plateaus of East Asia and North America, 

 we see that these two great continents of the Secondary epoch 



* Revista Argentina de Ciencia Natural, No. 4 (Sobre la distribution geografica de los 

 Creodontes, and letter to F. Ameghino). 

 f Nature, 1892, vol. xlvi, p. 12. 



