404 ADVANCED PHYSIOLOGY 



Page 78. To illustrate the action of an acid on the teeth, show the 

 result of putting hydrochloric acid on an egg shell. Rapid corrosion 

 follows. 



Page 79. The correctness of the text figure can be easily proved by use 

 of prepared slides of taste buds. See list of dealers. 



Page 80. The connection between the nose and mouth cavities 

 through the pharynx is easily shown by mecely noting that any breath 

 drawn in through the mouth can be expelled through the nose, or vice 

 versa. 



This point may also b3 illustrated by use of human skull, or if this is 

 not at hand, by the skull of cat, dog, rabbit, etc. 



Page 81. The salivary glands of a cat show readily as soon as the 

 skin is removed from the head, and in same location as in man. The 

 duct from the parotid gland passes across the cheek region and no dissec- 

 tion is required to show most of its length. 



Page 84. Ciliary action can be easily shown under high powers of 

 a compound microscope by mounting on a glass slide (in 0.6% salt solu- 

 tion) some ciliated cells scraped from roof of a frog's mouth, or a piece of a 

 clam's gill. A correct idea of cilia cannot be obtained otherwise. 



The surprising power of cili,. to move objects is demonstrated by remov- 

 ing the lower jaw and floor of mouth complete from frog after brain has 

 been destroyed. Keeping the surface of roof of mouth moist with normal 

 saline solution (0.6%) place on it a small wooden block, size of pea. It 

 will be moved along by the cilia. 



Page 84. 1. If one closes the nose passages by holding the nose between 

 the fingers, and then swallows, the noise in the ears shows that a passage 

 exists between them and the throat. 



A model of the human pharynx should be used in this connection. 



2. The several openings into the pharynx described in Chapter V 

 can easily be shown in a recently chloroformed frog. The glottis is a 

 longitudinal slit on a slight prominence at the back of the tongue. The 

 gullet is immediately back of the glottis. The posterior openings of the 

 nostrils are just back of the upper jaw, at the very front of the mouth. 

 The Eustachian tubes can be seen as wide openings at the junction of 

 upper and lower jaws ; a bristle can easily be passed into them co as to 

 demonstrate that the passage leads to the ear. 



