THE SEMI-APES. 255 



* 



diuarf slotlis (Bradypoda), and of the extinct unwieldy 

 giant sloths (Gravigrada). The enormous fossil remains 

 of these colossal herbivora suggest that the whole legion 

 is becoming extinct, and that the Edentata of the present 

 day are but a poor remnant of the mighty order of the 

 diluvial period. The close relations between the still 

 living South American Edentata and the extinct gigantic 

 forms which are found beside the latter on the same part of 

 the globe, made such an impression upon Darwin on his 

 first visit to South America, that they even then suggested 

 to him the fundamental idea of the Theory of Descent. (See 

 above, vol. L p. ISi). But it is precisely the genealogy of this 

 legion which is most difficult. The Edentata are pei'haps 

 nothing but a peculiarly developed lateral branch of the 

 Ungulata ; but it may also be that their" root lies in quite 

 another direction. 



We now leave the first main group of Placental animals, 

 the Indeciduata, and turn to the second main group, 

 namely, the Deciduata, or animals with decidua, which are 

 distinguished from the former by possessing a deciduous 

 membrane, or decidua, during their embryonal life. We 

 here meet with a very remarkable small group of animals, 

 for the most part extinct, and which probably were the 

 old tertiary (or eocene) ancestors of man. These are the 

 Semi-apes, or Lemurs (Prosimise) ; these curious animals 

 are probably the but little changed descendants of the 

 primaeval group of Placentalia which we have to consider 

 as the common primary form of all Deciduata. They have 

 hitherto been classed together in the same order with Apes 

 which Blumenbach called Quadrumana (four-handed). How- 

 ever, I regard them as entirely distinct from these, not 



