156 DE. H. r. STANDING ON SIJBFOSSIL 



strong cylindrical teeth (Plate X.). The angle of the mandibular symphysis of Pala'o- 

 propithecus again may be compared with that of some of the American forms. 



It seems necessary before concluding this section to say a few words as to the 

 possibility from a geological point of view of tlie existence in Madagascar during 

 Tertiary times of the Ape-like animals postulated by the foregoing argument. In the 

 absence of the direct evidence, either positive or negative, which the discovery of 

 Tertiary Primate remains either in Madagascar or on the African continent might be 

 expected to supply, we must be content with showing that there is strong presumptive 

 evidence for the truth of the hypothesis here advanced. 



There are certain main facts which, broadly speaking, are generally accepted 

 by geologists, though there are still divergences of view as to detail. In the first 

 place, there is evidence of an ancient land-connexion between Africa, Madagascar, and 

 India on the one hand, and between Madagascar, Africa, and South Amei'ica on the 

 other. In summing up the biological evidence as to the former continuity of land 

 between Africa and India, Dr. Blanford says * : "So far as I am able to judge, every 

 circumstance as to the distribution of life is consistent with the view that the 

 connexion between India and South Africa included the Archaean masses of the 

 Seychelles and Madagascar, that it continued throughout Upper Cretaceous times and 

 was broken up into islands at an early Tertiary date." With this the recently expressed 

 views of French palaeontologists are practically in harmony. Mons. Trouessart says : 

 " Je fais volontiers I'abandon, avec Mons. Boule, de toute relation continentale avec 

 YlrvAe a i^artiT de la fin du Cretace, car I'etude de la faune Malgache n'exige nullement 

 cette supposition." 



On the other hand, there seems evidence of a more recent connexion of Madagascar 

 with Africa. Baron, who has recently studied both the botany and geology of Mada- 

 gascar, comes to the conclusion that Madagascar was probably "joined to the African 

 continent during some part or parts or the whole of the Miocene (including Oligocene) 

 and early Pliocene periods." Baker also, from a comparative study of the floras of 

 Madagascar and of Africa, concludes that there must have been a warm period during 

 which (or some part of it) Madagascar was joined to the continent of Africa and also 

 to Mauritius, Bourbon, and the Seychelles. 



The evidence of a former land-connexion between Africa (including Madagascar) 

 and South America is even more striking. Without entering minutely into the details 

 of this evidence, a few facts relating to various groups of animals and plants may be 

 quoted. Thus among Lacertilia two genera of the typical American family of 

 Iguanidse occur in Madagascar. Two genera of Amphisbsenidse are represented both 

 in Africa and S. America. The Snakes especially give strong confirmation of the 

 former connexion of these land-areas ; in fact, to quote from Dr. Blanford, " the Ophidian 



* Presidential Address Geological Society, 1890. 



