The Capture, Preparation, and Preservation of Specimens 



Fig. 62.- 



■Tip of inflating-tube, with armature for 

 holding larval skin. 



for lessening the labor involved have been devised, some of which 

 are to be highly commended. 



" A comparatively inexpensive arrangement for inflating larvae 

 is a modification of that described in the ' Entomologische Nach- 

 richten ' (1879, vol. v, p. 7), devised by Mr. Fritz A. Wachtel 

 (Fig. 61). It consists of a foot-bellows such as is used by 

 chemists in the laboratory, or, better still, of a small cylinder 

 such as is used for holding gas in operating the oxyhydrogen 



lamp of a sciopticon. In 

 the latter case the com- 

 pressed air should not 

 have a pressure exceed- 

 ingtwenty pounds to the 

 square inch, and the cock regulating the flow from the cylinder 

 should be capable of very fine adjustment. By means of a rubber 

 tube the air is conveyed from the cylinder to a couple of flasks, one 

 of which contains concentrated sulphuric acid, and the other is in^ 

 tended for the reception of any overflow of the hydrated sulphuric 

 acid which may occur. The object of passing the air through 

 sulphuric acid is to rob it, so far as possible, of its moisture. It 

 is then conveyed into a flask, which is 

 heated upon a sand-bath, and thence by a 

 piece of flexible tubing to a tip mounted 

 on a joint allowing vertical and horizontal 

 motion and secured by a standard to the 

 working-table. The flow of air through 

 the tip is regulated by a cock. Upon the 



tip is fastened a small rubber tube, into the 

 r Fig. 63. — Drying-oven: 



free extremity of which is inserted a fine- a, lamp; B, pin to hold door 



pointed glass tube. This is provided °P en; C ' door open; D ' 

 r ° r glass cover. 



with an armature consisting of two steel 



springs fastened upon opposite sides, and their ends bent at right 

 angles in such a way as to hold the larval skin firmly to the 

 extremity of the tube. The skin having been adjusted upon 

 the fine point of the tube, the bellows is put into operation, and 

 the skin is inflated. A drying apparatus is provided in several 

 ways. A copper plate mounted upon four legs, and heated by an 

 alcohol-lamp placed below, has been advocated by some. A bet- 

 ter arrangement, used by the writer, consists of a small oven heated 

 by the flame of an alcohol-lamp or by jets of natural gas, and pro- 



46 ' 



