72 
HOW TO COLLECT 
Should it be found impracticable to proceed in 
the manner here advised, owing to the difficulty 
of making the specimen lie in the required position 
on its back, or from any other reason, it may be 
pinned in the ordinary way through the middle of 
the thorax from the dorsal side. In this case, 
however, the specimen must be pinned first (i.e. 
before it is mounted on the card disc) ; and if the 
fly has rows of bristles on the thorax, care should 
be taken to insert the pin between them, and not 
to damage them in any way. The specimen should 
be drawn two-thirds of the way up the pin, and 
the latter should then be thrust through the disc, 
holding the pin with the forceps below the specimen : 
mount the disc on a common pin, as in the first 
method. 
USE OF DISCS. 
The last thing to be done is to arrange the legs and wings as far 
as possible. The wings must be made to project at an angle from 
the body, and not allowed to remain closed over it ; if they can be got 
to remain at right angles to the body, so much the better. In the 
case of any specimen that is not too small and fragile, the wings can 
be best arranged, by means of the fine-pointed forceps, by making a 
gentle simultaneous pressure with the tips of the forceps at the base 
of each wing, repeating it until the wings assume the desired position. 
The legs also must be disposed symmetrically (and as far as possible 
in a natural position) on the card disc, so that all parts of them can 
be readily seen, and must not be allowed to remain crumpled up 
beneath the body, since important characters are often found upon 
them. In the case of a specimen with strong claws (such as one of 
the Robber-flies) it will generally be found possible to cause the legs 
to remain in the desired position by hooking the claws on the edge 
of the disc, gently drawing the legs out one after another by aid of 
a needle or one leg of the fine-pointed forceps. The manipulations 
in connection with the legs and wings must be performed as gently 
as possible, and care must be taken that bristles, hairs, or scales are 
not rubbed off in the process. As soon as these operations are 
