yA ON DISSECTION. 
8. Slides and coverslips, for mounting microscopical speci- 
mens. 
9, A blank note book, for drawing in; an HB pencil, and a 
piece of india-rubber. 
III—ON DISSECTION. 
The object of dissection is to separate the several parts and 
organs from one another, so as to define their boundaries and 
display clearly their relations to one another. Dissection con- 
sists, therefore, mainly in removing the “ connective tissue ” 
which binds the several parts to one another. 
The following rules should be carefully attended to :— 
1. Always pin down the animal you are dissecting firmly to 
the dissecting board. Never attempt to dissect a specimen 
that is not so fixed. 
2. In pinning out a dissection stick the pins in, not verti- 
cally, but obliquely, so that their heads do not get in the way 
or obscure the dissection. 
3. Never cut away anything until you are quite certain what 
it is you are removing. 
4. Always put the part you are dissecting slightly on the 
stretch ; e.g. when dissecting the bloodvessels or nerves of the 
throat, distend it by passing a small roll of paper or the 
handle of a seeker down the cesocphagus; or when dissecting 
the muscles of the leg, pin out the leg in such a position as to 
stretch the muscles you are cleaning. 
5. In cleaning bloodvessels or nerves always dissect along 
them and not across them; and avoid laying hold of them 
with the forceps. Similarly when cleaning muscles, dissect 
along their fibres and not across them. 
6. Fine dissections should always be done under water, which 
supports the parts and greatly facilitates the operation. A 
stream of water allowed to play gently on the dissection from 
time to time is often a valuable aid. 
7. The dissection of muscles, and still more of nerves, ‘is 
greatly aided by placing the specimens in spirit for a day 
before dissecting. 
8. Always keep your instruments clean and sharp. Be care- 
ful not to blunt your tine scissors or scalpel by using them for 
cutting hard parts. 
