20 ELEMENTS OF MAMMALIAN ANATOMY. 



of binomial nomenclature in accordance with which the 

 scientific name of every plant and animal is composed of 

 two parts, the generic and specific. Thus the house cat 

 is designated Felis domestica; the lion, Felis leo; the 

 dog, Canis familiaris; the wolf, Canis lupus; the pig, 

 Sus scrofa; the red deer, Cervas elephas; the elephant, 

 Elephas Africanus; the ourang-outang, Simia satyrus; 

 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 evap- 

 orates from the specimen exposed to the air, thereby 



rendering the parts dry and brittle, its 

 use has been largely supplanted by for- 

 malin. Formalin, CH 2 O, is often sold 

 under the names of formose, formol, 

 formine, formalosa, and formaldehyd. 

 It can be purchased for about thirty 

 cents a pound. For preserving any ani- 

 mal or plant, the concentrated 40% for- 



FIG. 1.- SPECIMEN 11 i i 1-1 i ,-, ,1 



J AR maldehyd is diluted with water in the 



proportion of ninety-five parts of the 

 latter to five parts of the former. It is evident, there-, 

 fore, 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 permanent preservation the glass jar with the 

 ground-glass cover should be used (Fig. i). 



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 red 



