20 



"by being compelled to teach not only Entomology, but also all the Natural Sciences — a 

 load amply sufficient to keep several men busy. 



For my own part, after many years of alternate collection and loss of Entomological 

 specimens, I almost abandoned the effort in despair after finding some of my cases filled 

 with webs, cocoons and moths of Tinea pellionella, etc., and most of the specimens either 

 destroyed or badly damaged. The task seemed hopeless without more time and attention 

 than I was able to give. I may say that I had for some years been using gasoline to kill 

 specimens, bub her« my use of it ended. Knowing, however, and feeling the utter impos- 

 sibility of teaching Entomology without specimens, I began to consider if it was not possible 

 to devise some fairly easy method of keeping my cases free from these and other pests, so 

 as to bring the labour within reasonable limits. I first reduced their capacity, in order 

 that they and their contents might be as compact as possible, and also that " all the eggs 

 might not be in the same basket." My cases are now made about twenty inches by 

 twelve, and about one inch and a quarter in depth. Their sides and ends consist of black 

 walnut, well jointed and about one inch thick. The glass top is set in a rabbet with 

 putty, and is consequently quite insect-proof. The back consists of soft pine or tulip 

 wood about three-eighths of an inch in thickness, and is attached to the frame by twelve 

 screws. This back, when covered with a coat of manilla paper, is generally soft enough to 

 take and hold the pins. But in addition I often line the bottom with sheet-cork, or as the 

 cost of this material soon mounts too high, when as many cases are made as even a small 

 cabinet requires, I generally employ instead of it some one of the forms of packing that 

 are used by druggists — either the strawboard with a backing of cork chips, or the corrugated 

 paper made by Thompson & IsTorris, of Islington, London, and Prince Street, New York. 

 Either of these is very effectual, nearly as good as sheet cork, and merely nominal 

 in price. 



By setting the glass myself and doing any finishing required for effect, I can obtain 

 these cases at about sixty cents each, and in this way a collection, amply sufficient for all 

 the purposes of teaching, may be set up for a comparatively small outlay. 



By screwing the back tight up and avoiding opening the cases except in the cold 

 weather, I largely reduce the chances of mischief. All the specimens obtained during a 

 season are placed in a temporary case until the time for assorting arrives. 



It is, of course, impossible in collecting, and especially in exchanging, to totally 

 exclude parasites. Indeed, it is more than likely that many insects are infested when 

 they are caught. The disinfection of every specimen singly is a very tedious process, and 

 in my own experience proved a very serious barrier to collecting. I therefore now 

 arrange all the specimens in their desired places without regard to their condition in this 

 respect, and then disinfect them wholesale in the following manner : I have a zinc tray 

 of rather larger size than the cases, and about two inches deep. This I fill with gasoline 

 and then set the whole case, or at least the back, with its charge of insects in it, and allow 

 it to soak for a few minutes until everything is saturated with the liquid. Two or three 

 minutes are usually quite sufficient. I then remove them, drain off the superfluous gaso- 

 line, and in a few minutes they are dry and ready to be set back and screwed up again. 



By this simple means I secure the purity not only of the insects, but of the case also, 

 from parasitic life, for nothing living can endure this ordeal. So far as opportunity has 

 offered for observation I believe that the operation is equally fatal to eggs. 



I need hardly remark that there is no trouble to be apprehended with any order 

 except the Lepidoptera. Even with these I do not hesitate to employ the same method, 

 and find no ill effects from it. Their delicate plumage is not perceptibly injured by free 

 saturation with this very volatile liquid. 



Since adopting this plan, I find it only necessary to glance over my cases occasionally 

 during the summer, and if the eye detects any sign of mischief, even the minute dust that 

 indicates the presence of the mite (A. divinatoria or pulsatoria), I take out the case, 

 loosen the back screws, and place the whole in the gasoline. In five minutes it is 

 replaced with the certainty that all life is extinct. 



As I said at the outset, Entomologists with plenty of time will not probably feel 

 much interest in the suggestions here made, but I find, in my own experience, that the 



