BLOWING CATERPILLARS. 267 



nation, the tube can be opened and closed again after a little prac- 

 tice (Deutsche Ent. Zeits., xxxi., 1887, heft 1). 



Preserving Larvae Dry. A good method of preserving 

 larvaa dry, adopted at Dresden, is to squeeze out the in- 

 testines through a hole made near the anal extremity of the 

 larva, then to insert a fine straw, after which it may be put 

 in a glass vase, which is placed in a tin vessel and held over a 

 lamp; the larval skin is blown while suspended over the 

 lamp, by which the skin dries faster. It may be done with 

 a small tube or blow-pipe fixed at the end of a bladder, 

 held under the arm or between the knees, so as to leave the 

 hands at liberty; and the straw which is inserted into the 

 body of the larva may be fastened by a cross-pin stuck 

 through the skin, and thus retained in its proper position 

 throughout the process of blowing.* M. P. Chretien, of 

 Paris, who has had wide experience in preparing caterpil- 

 lars, writes me describing his method of emptying larvae as 

 follows: It is sufficient to make with the point of a pair of 

 scissors a very small cut in the anus of the caterpillar, 

 between the last pair of legs; then to extend the caterpil- 

 lar upon a piece of old linen for the purpose of soaking up 

 the fluids of the larva; then to press the caterpillar, begin- 



* Mr. F. A. Wachtel fastens the skin to the fine point of a glass tube 

 in blowing, and by this method the last abdominal segment preserves 

 its form. His method is described and the apparatus figured in the 

 Bulletin of Ihe Brooklyn Entomoloeical Society, i. 94. See also 

 " Scudder's Butterflies" (H Holt & Co.); Can. Ent. vi. 107; or Amer. 

 Nat., viii. 321. For the serious study of larva?, alcoholic specimens 

 should supplement the blown ones; for in many caterpillars, notably 

 the Geometrids, the characters of the anal legs and supra-anal plates 

 (distorted or lost in blown specimens) are only to be observed in living 

 or alcoholic examples. Mr. A. W. P. Kramer, after drawing out the 

 intestines, etc., takes those protruding parts between his fingers and 

 inserts the point of a finely drawn-out glass tube till it enters the vent 

 two or three millimetres, "then secures the intestine to the tube with a 

 thread, and makes the juncture air-tight with a little collodion. He 

 then fills the larva with air, and lets it dry for from one to six days. 

 The advantages claimed for this process are that no heat is required, 

 and that one has greater facilities for giving the larva a natural posi- 

 tion. The air-pressure can be obtained with a toy red-rubber balloon. 

 Bull. Brooklyn Ent. Soc., vii. 93. 



