A MANUAL OF ZOOLOGY ^ 69 



in paraffin, and cutting in a microtome. Stain "in toto" 

 in borax or para carmine. Note the following: the peri- 

 otic capsule, the vestibule, the ductus endolymphaticus, 

 the semicircular canals, the auditory nerve, the eustach- 

 ian tubes, the tympanic membrane, the columella. 



THE REPRODXJCtlVE SYSTEM— In a male specimen 

 locate the testes as a pair of yellow, oval bodies, on the 

 ventral surface of the kidneys. The vasa efferentia are 

 several tubes leading from' the testes to the kidneys. They 

 carry the sperm cells, into the kidneys from which they 

 pass through the ureters which act as vas 'deferens. They 

 finally open into the cloaca. Locate the vesicula seminalls 

 as a large pouch on the vas deferens before they open into 

 the cloaca. Note the following openings into the cloaca: 

 the large intestine, the ureters, and the bladder. What is 

 the nature of the bladder? .Are there any openings out of 

 it? Compare the female frog with the above. Locate the 

 ovaries. Trace out the oviducts. Does the female frog 

 have ureters as well as oviducts? Compare with the 

 male. Note the openings into the cloaca: the- bladder, 

 the oviducts, the ureters. How does th? number of open- 

 ings compare with those in the male? 



REPTILIA 

 The Turtle. 



NOTE — The work on the- turtle should be one of con- 

 tinuous comparison with the lower forms, especially with 

 the frog. 



EXTERNAL STRUCTURES— The shell Of the turtle 

 consists of a dorsal part, the carapace, and a ventral por- 

 tion, the plastron. -These are united at the side by the 

 bridges. The carapace is made up of a definite number of 

 central plates surrounded by a regular border of smaller 

 ones. What is the number of each kind? How many 

 plates in the plastron? Is it divided into distinct parts? 

 Is it movable? What is the purpose of the shell? Can 

 the head, tail, and legs be entirely drawn into the shell? 

 Make a sketch of the ventral surface of the animal. Note 

 the general shape of the head. Find the nostrils. Into 

 what do they open? Note the size, shape, and position 



