538 HENEY F. BLANEOBD ON THE 



may also be traced between the vegetation of "Western Tropical 

 Africa and that of the peninsular chain/' quoting, at the same time, 

 some cases of specific identity. 



Palaeontology, physical geography, and geology, equally with the 

 ascertained distribution of living animals and plants, offer then their 

 concurrent testimony to the former close connexion of Africa and 

 India, including the tropical islands of the Indian Ocean. This 

 Indo-Oceanic land appears to have existed from at least early 

 Permian times, probably (as Professor Huxley has pointed out) up 

 to the close of the Miocene epoch ; and South Africa and Peninsular 

 India are the existing remnants of that ancient land. It may not 

 have been absolutely continuous through the whole of this long 

 period. Indeed the Cretaceous rocks of Southern India and Southern 

 Africa, and the marine Jurassic beds of the same regions, prove that 

 some portions of it were, for longer or shorter periods, invaded by 

 the sea ; but any break of continuity was probably not prolonged ; 

 for Mr. Wallace's investigations in the Eastern Archipelago have 

 shown how narrow a sea may offer an insuperable barrier to the 

 migration of land-animals. In Palaeozoic times this land must have 

 been connected with Australia, and in Tertiary times with Malayana, 

 since the Malayan forms with African alliances are in several cases 

 distinct from those of India. "We know as yet too little of the 

 geology of the eastern peninsula to say from what epoch dates its 

 connexion with Indo-Oceanic land. Mr. Theobald has ascertained 

 the existence of Triassic, Cretaceous, and Nummulitic rocks in the 

 Arakan coast-range ; and Carboniferous limestone is known to occur 

 from Moulmein southwards, while the range east of the Irawadi is 

 formed of younger Tertiary rocks. .From this it would appear that a 

 considerable part of the Malay peninsula must have been occupied 

 by the sea during the greater part of the Mesozoic and Eocene 

 periods. Plant-bearing rocks of Eaniganj age have been identified 

 as forming the outer spurs of the Sikkim Himalaya ; the ancient 

 land must therefore have extended some distance to the north of the 

 present Gangetic delta. Coal, both of Cretaceous and Tertiary age, 

 occurs in the Khasi Hills, and also in Upper Assam, but in both 

 cases associated with marine beds ; so that it would appear that in 

 this region the boundaries of land and sea oscillated somewhat during 

 Cretaceous and Eocene times. To the north-west of India the ex- 

 istence of great formations of Cretaceous and Nummulitic age, 

 stretching through Baluchistan and Persia, and entering into the 

 structure of the North-west Himalaya, prove that in the later 

 Mesozoic and Eocene ages India had no direct connexion with 

 "Western Asia ; while the Jurassic rocks of Cutch, the Salt range, 

 and the Northern Himalaya show that in the preceding period the 

 sea covered a large part of the present Indus basin ; and the Triassic, 

 Carboniferous, and still more ancient marine formations of the 

 Himalaya indicate that, from very early times till the upheaval of 

 that great chain, much of its present site was for ages covered by 

 the sea. i 



