} 
ON THE PRESERVATION OF PARASITIC HYMENOPTERA. 33 
will be found very useful, and is cheap at half-a-crown; 
‘Pinacographia’ is very valuable, but expensive. 
In the subsequent papers these six families of our Ichneu- 
monide will be treated of in both systematic and biological 
detail. 
ON THE PRESERVATION OF PARASITIC HYMENOPTERA. 
By Epwarp Capron, M.D. 
Ir is of above all things necessary to determine the names of 
the smaller species of Hymenoptera, that they should be set in 
such a manner that all the important characters should be plainly 
visible, and that the thorax should not be entirely destroyed by a 
pin as large as itself, which is generally the condition in which I 
receive specimens from correspondents. If killed by the ordinary 
methods, such as cyanide of potassium, laurel, or chloroform, the 
insects almost always die with the wings folded vertically and the 
legs contracted, and so rigid are the muscles of this class that, 
unlike Lepidoptera, no amount of relaxing can be effected by 
_ moisture, and the insect is generally useless. After many trials 
I have found the plan I adopt so successful that I think it is 
worthy the attention of those who intend to study this most 
interesting group. In the first place, however, it is necessary to 
bring the insect home alive, and not damaged by its capture; 
nothing spoils the appearance of a fine Ichneumon so much as a~ 
missing leg or antenna. ‘These insects are so active in a net 
that they will often give you the slip before you are aware of it 
and escape altogether. My plan is as follows :— 
I take with me a pocket full of medium size chip-boxes, or 
rather large pill-boxes, and a wide-mouth bottle with a large 
cork, charged moderately with cyanide of potassium. I place this 
over the insect in the net, and hold my hand on the top (the net 
being between) until the insect is just stupefied but not dead. 
With the smaller ones this occurs almost at once. I then remove 
it, and examine it with a lens to see if it is worth saving; if it is 
I transfer it to one of the boxes. By the time I reach home the 
insect will be as lively as ever, and I then kill it in the following 
manner :—I take a large white basin and fill it with quite boiling 
water. When it has cooled a few degrees I take each box and 
give it a tap to send the insect to the bottom, and then suddenly 
F 
