36 



COMPAEA.TIVE PHYSIOLOGY. 



Protozoa (amoeba, vortioella, etc.). 

 Coelenterata (sponges, jelly-fish, polyps, etc.). 

 Eohinodermata (star-nsh, sea-uroliiDS, etc.). 

 Inverte- Vermes (worms). 

 brata. Arthropods (crabs. Insects, spiders, etc.). 



MoUusoa (oysters, snails, etc. ). 

 Animal MoUusooidea (mosB-like animals). 



Kingdom. '' ^ Tunicata (ascidians). 



(Pisces (fishes). 

 Amphibia (frogs, menobranolms, etc.). 

 Eeptilia (snakes, turtles, etc.). 

 Aves (birds). 

 Mammalia (domestic quadrupeds, etc.). 



The above classification (of Clans) is, like all such arrange- 

 ments, but the expression of one out of many methods of view- 

 ing the animal kingdom. 



For the details of classification and for the grounds of that 

 we have presented, we refer the student to works on zoology ; 

 but we advise those who are not familiar with this subject, 

 when a technical term is used, to think of that animal belong- 

 ing to the group in question with the structure of which they 

 are best acquainted. 



Man's Place in the Animal Kingdom. 



It is no longer the custom with zoologists to place man in an 

 entirely separate group by himself ; but he is classed with the 

 primates, among which are also grouped the anthropoid apes 

 (gorilla, chimpanzee, orang, and the gibbon), the monkeys of 

 the Old and of the New World, and the lemurs. So great is 

 the structural resemblance of man and the other primates that 

 competent authorities declare that there is more difference be- 

 tween the structure of the most widely separated members of 

 the group than between certain of the anthropid apes and man. 



The points of greatest resemblance between man and the 

 anthropoid apes are the following : The same number of verte- 

 brse ; the same general shape of the pelvis ; a brain distinguish- 

 ing them from other mammals ; and posture, being bipeds. 



The distinctive characters are size, rather than form of the 

 brain, that of man being more than twice as large ; a relatively 

 larger cranial base, by which, together with the greater size of 

 the jaws, the face becomes prominent ; the earlier closure of 

 the sutures of the cranium, arresting the growth of the brain ; 

 more developed canine teeth and difference in the order of erup- 

 tion of the permanent teeth ; the more posterior position of the 

 foramen magnum ; the relative length of the limbs to each 



