INTRODUCTION 9 



domestica; the lion, Felts leo; the dog, Canis fa miliar is; the wolf, 

 Cams lupus; the pig, Sus scrofa; the red deer, Cervus elephus; 

 the elephant, Elephas Africanns; the orang-outang, Simla saty- 

 rus; and man Homo sapiens. 



METHODS OF PRESERVING MATERIAL 



Alcohol has been widely used as a preservative, but owing 

 to the fact that it is expensive and quickly evaporates from 

 the specimen exposed to the air, thereby rendering the parts 

 dry and brittle, its use has been largely supplanted by formalin. 

 Formalin, CH^O, is often sold under the names of formose, 

 formol, formine, formalosa, and formaldehyd. It can be pur- 

 chased for about thirty cents a pound. For preserving any 

 animal or plant, the concentrated 40% formaldehyd is diluted 

 with water in the proportion of ninety-five parts of the latter to 

 five parts of the former. It is evident, therefore, that one pound 

 of formaldehyd will make about ten liters of preserving fluid. 



The specimens may be kept a year or two without changing 

 the formalin in ordinary stone jars with covers, but for perma- 

 nent preservation the glass jar with the ground-glass cover 

 should be used. 



Preparation of Vascular System. — To render the vessels 

 plainly visible and distinguish the arteries from the veins, it is 

 advisable to inject the former with a yellow or red mass and the 

 latter with a blue mass. These fluid masses should be of such a 

 character as to harden in a short time after injection, so that 

 they will not run out when the vessels are cut during dissection 



A syringe of hard rubber, having a capacity of about two 

 ounces, serves very well for injection. A cannula of correct 

 size may be had by asking the druggist for the filling cannula 

 of the Parke Davis serum syringe. The end to be inserted into 

 the blood-vessel should be ground off obliquely and smoothly 

 on a whetstone. The connection between the cannula and 

 nozzle is formed by stiff rubber tubing which should be securely 

 tied to the cannula (Fig. i). 



