CHAPTER: VI. 
LABORATORY WORK. 
e 
THE account which follows is from the necessities of the 
case greatly condensed, many points of great importance be- 
ing entirely omitted. This account is intended for the 
beginner only. For more extended directions the student 
is directed to the list of books at the end of this chapter ; 
those of Huxley and Martin, Tulk and Henfrey, Burden- 
Sanderson, Stricker and Ranvier giving the best and most 
detailed instructions. Beale’s book, like most of his other 
works, is in many respects unreliable. 
DISSECTING. 
All small objects should be dissected under water or a 
mixture of alcohol and water, as these media tend to support 
and float the parts and tissues which otherwise would mat to- 
gether to a greater or less extent, and thus obscure the dis- 
section. Dissecting troughs are used for this purpose. 
These are usually made of tin (fig. 36). These troughs, for 
ordinary work, should be about six by eight inches square, 
and one and a half to two inches in depth. Small tin slips 
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