424 DR. C. F. SONNTAG ON THE ANATOMY, 



the animal whose anatomy is described in this paper with those 

 in Man the following results are obtained : — 



Chimpanzee. Man. 



End of heel to tip of middle digit .. . 7'4 ins. 8-4 ins. 



Hallux and its metatarsal bone 4*0 ,, 4'5 „ 



Hallux without metatarsal bone ... 2*2 ,, 2-3 ,, 



Length of metatarsals 2-5 2*0 ,, 2*5 „ 



Length of phalanges: — 



second digit 2*5 ,, 1"8 „ 



third „ 2-8 „ 



fourth ,, 2-5 ,, 



fifth „ 2-3 „ 



Total length of second digit 4-5 ., 4-3 „ 



It is thus seen that in the Chimpanzee the phalanges of digits 

 2-4 f>,re more than a third of the length of the foot, but the fifth 

 digit is less thon a third ; but in Man they are less than a 

 quarter of the length of the foot. The hallux in the Chimpanzee 

 is shorter than the other digits, but it is slightly longer than 

 them in Man. In the Chimpanzee the relative lengths of the 

 digits are as in a hand, and the digits act towards or from a line 

 passing through the middle digit ; in a foot the basal line passes 

 through the second digit. All these data show that the pelvic 

 extremity in the Chimpanzee is terminated by a hand. And if 

 the grasping action of the human hand be taken as a pattern it is 

 even more effective than the hand which terminates the pectoral 

 extremity. The hind hand is not employed as an exploring organ, 

 and its grasping action is chiefly an aid to progression, so 

 Humphry (26) thinks that the term " chiropod " best describes it. 

 And he makes the following important statement : — " Whichever 

 term is used it must not be forgotten that the configuration on 

 which it is based is not peculiar to the monkeys, but is common 

 to them with some other tree-roving animals, such as Iguanas 

 and Opossums. In human beings, who are born without arms, 

 the foot can be educated to take the place of the missing hands. 

 And medical literatui'e contains records of such persons who 

 could grasp objects and carry out complex movements, such as 

 painting, with their hallux and foot digits. These cases have 

 been adduced by some writers to prove that the leg of the ape 

 is also terminated by a foot. They do not really disprove the 

 views stated above for: — 1. The proportions of the hallux and 

 digits to each other and to the whole foot are normally foot-like ; 



2. The middle line, or basal line, runs through the second digit ; 



3. The hallux can be abducted, but it is not really opposable; 



4. The prime work is to act in conjunction with the other 

 characters of the leg in forming a strong supporting basis for 

 the body. 



The joints between the occipital bone, atlas, and axis differ 

 from tho.-<e in Man. The inferior cms of the cruciate ligament 

 is absent, and there are additional strengthening bands. No 



