42 THE entomologist's record. 



that has settled on a wild parsley head in yonder flowery mead. How much 

 he wishes that his prisoner could be preserved by some method which 

 would make it remain " a thing of beauty and a joy for ever" — well not 

 quite "for ever" — but at any rate for his own brief lifetime. He 

 transports it safely home, and spends the evening in reading up all he 

 can find about the order " Lepidoptera '' in such books as his library 

 happens to contain ; most probably he can find nothing about the 

 subject except some very " general " information in an Encyclopaedia. 

 Then, perhaps, on the morrow he makes inquiries as to whether there 

 is anyone in his neighbourhood who knows about such things. The 

 upshot of his investigations is that Entomologists are very much divided 

 in opinion as to the best way of killing any insect they may catch. 

 Laurel leaves, cyanide bottles, chloroform and ammonia, all have their 

 advocates ! How is the tyro to decide when experts differ? There is 

 no doubt a good deal to be said for each of these four methods. Let 

 us say a few words on each, more for the sake of inviting comment 

 from our readers, than of settling such a knotty point. 



(i). Young laurel leaves, crushed and placed in an air-tight tin, will 

 deprive an insect of life almost immediately, and will, so say its 

 advocates, keep an insect beautifully relaxed — for a moderate period at 

 any rate — until it may be convenient to set it out. Laurel leaves are 

 easily obtainable, which is a great point in favour of this system, but on 

 the other hand, it is a great drawback to their use that they require 

 renewing frequently, so that this method is but a clumsy one at best. 



(2). It is the prussic acid in laurel leaves that proves so fatal to insect 

 life, and the same principle is contained in cyanide of potassium, 

 whereof the cyanide bottle is composed, a layer of plaster of Paris being 

 superimposed. These cyanide bottles are comparatively permanent, 

 most of them not requiring the cyanide to be renewed for some two or 

 three years, others not for ten or twelve, the difference no doubt being 

 brought about by a loose or closely fitting bung. The temperature, 

 also, affects the potency of the cyanide very much. The bottle kills 

 and relaxes insects much more rapidly in hot weather than in cold. In 

 any case, no sooner is the specimen dead than rigor mortis supervenes, 

 and does not pass away till about the twentieth hour in the case of 

 smaller insects, such as CRAMBiDiE and Tortrices, and not until about 

 the fiftieth in the case of larger species. But directly this rigidity 

 departs, the specimen is in a most beautifully relaxed state, and every 

 part can be moved readily and arranged in loco quo with the utmost 

 ease. Specimens treated in this way last for many years, and are 

 wonderfully exempt from mould, the lepidopterist's most deadly enemy. 



Whatever mode of killing he may adopt, let the beginner most 

 earnestly beware of pinning his captures after they are dead, and 

 placing them in a zinc relaxing box. Most certainly such specimens 

 will mould in years to come, and then their pristine beauty will dis- 

 appear for once and aye. 



(3). Some collectors object to cyanide, on the ground that specimens 

 subjected to it are very liable to verdigris thereafter ; it may be so, but 

 can they say that any system offers a remedy for this? Of course the 

 great objection to the use of cyanide, is that one cannot set out one's 

 captures immediately on coming home, and if they are not set out just 

 at the proper time, they become stiff again and difficult to manipulate. 



