492 ELEMENTARY ANATOMY. [LESS. 



(n) He never has gills at any time of life. 



(12) His heart has two ventricles. 



(13) All the blood of his body passes through the lungs. 



(14) There is no communication, in the adult, between the 



veins and arteries, save by the capillaries. 



(15) He has but one aortic arch. 



(16) His alimentary canal does not terminate in a cloaca. 



(17) He has a complete diaphragm. 



(18) His kidneys replace transitory Woolffian bodies. 



(19) His blood-corpuscles are not nucleated. 



(20) He is provided with true salivary glands. 



1 8. Man is distinguished from REPTILES in that 



(1) His skull has a " petrous bone " and a mandible formed 



of two united pieces directly suspended from the 

 squamosal. 



(2) His auditory ossicles are minute, and take no part in 



suspending the mandible. 



(3) His vertebras at first have terminal epiphyses. 



(4) His skin is furnished with hair. 



(5) His cerebrum is excessively large, with a corpus cal- 



losum, and his corpora quadrigcmina are very small 



(6) His olfactory nerves traverse a cribriform plate. 



(7) His ear has a spiral cochlea. 



(8) All the blood of his body passes through the lungs. 



(9) There is no communication, in the adult, between the 



veins and arteries, save by the capillaries. 

 (10) He has but one aortic arch, 

 (n) His alimentary canal does not terminate in a cloaca. 



(12) He has a complete diaphragm. 



(13) The whole tarsus moves freely on the tibia, and there 



is no intertarsal joint. 



Man also differs from all Reptiles except the Crocodilia in 

 that 



(14) His blood-corpuscles are not nucleated. 



(15) His heart is provided with two completely distinct 



ventricles. 



(16) His posterior nares open far back within the mouth. 



19. Man is distinguished from BIRDS in that 



(i) His skull has a "petrous bone " and a mandible formed 

 of two united pieces directly suspended from the 

 squamosal. 



