THE CANADIAN ENTOMOLOGIST. 355 



MOUNTING INSECTS FOR THE ^IICROSCOPE. 



BY J. R. DE LA TORRE BUENO, WHITE PLAINS, N. Y. 



Dr. Packard's little book, " Entomology for Beginners," while not 

 exactly adapted to mere tyros, is really most suggestive to such as have 

 gone more deeply into the science. Its las^t chapters on dissection and 

 the preparation of insects for the microscope are especially useful, and 

 contain many helpful hints. From them I gathered my first notions of the 

 use of alkaline solutions for cleaning material, and of turpentine and 

 carbolic acid as cleaning and fixing agents. From Professor Gage's book, 

 " The Microscope," I learnt much of technique, and among other things 

 the use of carbol turpentine. 



In my work in breeding water-bugs, it has been my endeavour to 

 dissect where possible or necessary, and to mount entire where the size of 

 the insect permitted, for the microscopic study of anatomy, vvhich is a far 

 more satisfactory method than the examination of the entire insect by 

 means of a hand magnifier, or even under the microscope by reflected light. 



My first work was very orthodox. My dissections and bugs were 

 passed through different grades of alcohol, then through turpentine, and 

 finally cleared by means of oil of cloves. From Professor Gage's book I 

 absorbed the idea that all the gradual changes in the alcohol might be 

 advantageously omitted, which was done, and by various steps not 

 necessary to detail, my present procedure was evolved. It must be 

 borne in mind, however, that it is not my aim to bring out details of 

 internal anatomy, such as muscular structure, nervous or digestive systems, 

 etc., but to prepare the insect for the Study of its external organization. 



The simplest process is by the use of carbol turpentine. This I have 

 prepared by mixing approximately equal parts of carbolic acid crystals 

 with spirits of turpentine. Gage's exact formula for this is 40 cc. carbolic 

 and 60 cc. turpentine. Into this the living insect is plunged, and it ceases 

 to struggle in a minute or less. In general, the legs and wings are spread 

 out when the insect finally succumbs, and no further arrangement is 

 necessary for mounting. After 24 hours or so, or even as little as 12, it is 

 possible to mount. In fact, the longer the time that elapses, the harder 

 and more brittle the insect becomes, so that there is danger of breaking 

 off appendages by the mere weight of the cover glass. Flies killed in 

 this medium extrude the tongue most beautifully. 



For dead insects from the cyanide bottle the method is slightly 

 different. These are put at once into 95% alcohol, and after dehydration 



October, 1908 



