HP 



Chapter I 



LEMUR MONGOZ, ITS BRAIN AND BEHAVIOR 



Its Position among the Primates; Measurements and Brain Indiees; Surface 

 Appearance 0/ the Brain; Internal Structure of the Brain Stem in Cross Section 



"^HE lemurs, so called because of their nocturnal and ghostly habits, 

 represent the lowest level of primate organization. In all, there are 

 some fifty species of these animals referable to seventeen genera. 

 Thirty-six of these species are indigenous to Madagascar and its small 

 adjacent islands. The remaining species have their habitat in Ethiopian and 

 oriental regions. It is a fact of much interest that the rest of the world is 

 quite devoid of these animals, although fossil remains indicate that the 

 lemurs were much more widespread throughout the globe in some earlier 

 geological period. 



External Appearance of the Lemur (Figs. 5, 6 and 7) 



The external appearance of the lemurs justifies the establishment of a 

 suborder to contain these animals. They are readily distinguished from the 

 apes and monkeys constituting the higher suborder of primates. One impor- 

 tant distinguishing feature is the head, which in lemurs is more like that of 

 the fox and is drawn out into a long muzzle. The face lacks the humanoid 

 expression characteristic even of the lower apes. The tail, which may be long, 

 is not prehensile; cheek pouches do not develop, nor do integumental callos- 

 ities occur, although all these characters are frequently met with in the apes. 



The lemurs have certain striking resemblances to other primates, 

 especially in the opposable fingers and toes, flattened digits and pectoral 

 mammae. In all lemurs the second toe is provided with a sharp nail entirely 



