io6 
When an excess of fluid is present, slide ofl the cover- 
glass. The flattened mid-gut will probably remain 
attached to the coverglass. 
Wash in water, and stain lightly with methylene 
blue. Wash in water and allow to dry. Warm 
gently to ensure complete dryness, and place the 
coverglass, mid-gut downwards, upon a drop of balsam 
upon a slide. 
The muscular fibres and other structures of the 
mid-gut will be well exhibited. The zygotes will be 
stained rather a dark blue. If not too darkly stained, 
the pigment of the zygotes will have the appearance 
it had in the fresh specimen. 
Method 3.—For more minute histological examina¬ 
tion, imbed the stomachs, or the whole mosquito, in 
paraffin (p. 46). 
To Dissect Out the Salivary Glands 
This is quite a simple proceeding if it be remem¬ 
bered where they lie. They are intra-thoracic 
structures, and they commence at the hinder portion 
of the neck and end opposite the first pair of legs. 
They lie ventrally, in fact, roughly speaking, they lie 
just above the origin of the first pair of legs (Fig. 42). 
The simplest and most rapid method, and the one 
that hardly ever fails, is the following :— 
1. Place the mosquito in a drop of salt solution 
on its right side, with the head pointing towards you, 
as you dissect. 
2. Place the needle of the left hand on the thorax 
to steady it, and place the needle of the right hand 
on the back of the head and make steady gentle traction. 
3. If done carefully, it will be seen that the head 
has pulled out a little mass of white tissue from the 
