FEB., 1912. MAMMALS OF ILLINOIS AND WISCONSIN CORY. 479 



and one species, H. sapiens, which is represented by various races in 

 different parts of the World. 



The principle characters which distinguish the families belonging 

 to the Anthropoidea from their nearest allies, the Lemuroidea, may 

 briefly be summarized as follows: 



Orbit of skull largely separated from the temporal fossa by a plate 

 of bone; lachrymal foramen situated inside the margin of the orbit 

 instead of outside; upper incisors without diastemata (gaps between 

 the teeth) ; second digit of hand well developed and second digit of foot 

 with flattened nail, except in the Marmosets (Hapalida); cerebral 

 hemispheres highly developed and nearly or quite concealing the cere- 

 bellum; uterus not bicornate; placenta discoidal and deciduate; mam? 

 mae always thoracic, never abdominal. 



Family HOMINID^. Man. 



Aside from the supposed distinctive psychological characters attrib- 

 uted to members of this family, the following are the most important 

 anatomical differences which distinguish Man from the highest Apes: 

 Size and shape of the non-opposable hallux (which aids in assuming an 

 upright position in walking); relative shortness of the arms; 12 rib- 

 bearing vertebras; thumb relatively larger and with greater mobility; 

 skull rounded and smooth (not ridged as in the Apes) and face less 

 projecting; cerebral hemispheres greatly developed; absence of pro- 

 jecting canines, etc. Various other characters, such as the usual absence 

 of the scansorius muscle and the rudimentary character of the ear 

 muscles, are often cited, but the occasional presence of the former and 

 functional activity of the latter greatly detract from their value. 

 The same may be said of the apparent absence of hair on the greater 

 portion of the human body, as many abnormalities occur, and in any 

 event the difference is evidently only in extent of development. 



There is no such development of the larynx in the human species 

 as is shown in the large throat pouches of various Anthropoids; and 

 as Beddard remarks, ''The minute diverticula of that organ, known 

 to human anatomists as the ventricles of Morgagni, alone remain to 

 testify to the former howling apparatus in the ancestors of Man."* 



This does not necessarily imply that the original type of mammal 

 from which the modern races of men have sprung was an Ape. That 

 both Man and Ape are descended from a common ancestor has strong 

 arguments in its favor, but we do not know what that ancestor was like. 



* Mammalia, London, 1902, p. 589. 



