1 24 ANIMALS 



(u) Study the internal surfaces of a mammalian stomach and 



intestine, 

 (v) The heart of a mammal. Sketch the organ as a whole showing 



auricles, ventricles and the aortic arch. 

 (w) In a freshly killed turtle observe the beat of the heart noting the 



order of the beat in auricles and ventricle, 

 (x) Observe the circulation of the blood in the tail of a tadpole, the 



web of a frog's foot or the gills of a larval amphibian, 

 (y) In an injected frog trace the principal arteries, viz: The truncus 



arteriosus which divides into three arches: 



1. The Carotid Arch with its branches. 



(a) The external carotid. 



(b) The internal carotid. 



2. The Systemic Arch with its branches. 



(a) The subclavian. 



(b) The dorsal aorta from which arise: 



1. The coeliaco-mesenteric. 



2. The urinogenital. 



3. The iliac. 



3. The Pulmo-cutaneous with its branches. 



(a) The pulmonary. 



(b) The cutaneous. 



(z) An injected mammal may be studied as in y. 



(a') Study the lungs of a frog or turtle from which the liver and 

 stomach have been removed. Trace the trachea and bronchi 

 from the glottis to the lungs. Study the internal structure of a 

 lung which has been laid open. 



(b') In preparations of a mammalian lung note the structure of the 

 trachea, the division of the lung into lobes and the internal 

 structure of a lung. 



(c') In a male frog from which all other organs have been removed 

 observe the testes, the kidneys and the ureters. 



(d') In a female frog observe the ovaries and the oviducts. 



(e') Compare a mammal (rat) with the frog with regard to the excre- 

 tory and reproductive organs. 



CLASSES OF ANIMALS 



99. The following outlines may be used to extend the laboratory 

 studies to some of the other more important phyla and classes. 



