MOUNTING SPIDERS. 29 



paper, otherwise the hairs are apt to drop off. Then, holding 

 the larva in the left hand, enlarge the vent slightly below with 

 a vertical cut of the scissors, and next press the extremity 

 of the body with the fingers so as to force out the contents 

 of the rectum ; repeat the operation a little farther forward, 

 and so on, a slight additional portion of the contents of the 

 body being gently pressed out each time. Great care should 

 be exercised not to abrade the skin or get the exterior soiled 

 by the expelled portions. When a portion of the intestine 

 is extended, it should be seized with the forceps and, hold- 

 ing the head in the left hand, the tube should be forcibly 

 but steadily torn from its attachments bringing with it most 

 of the contents of the body. 



The lamp is now lighted and placed under the oven ; and 

 a straw taken of a proper size to enter the enlarged vent ; 

 having cut off one end diagonally it is moistened and 

 carefully inserted into the opening for about a quarter of an 

 inch, and then pinned through the straw and anal plate with 

 a delicate insect pin. The caterpillar is then inflated with the 

 breath, taking care not to use too great a pressure, and then 

 extended horizontally in the oven, the inflation being con- 

 stantly continued. The posterior end should be dried first 

 (by keeping it in the hottest portion) and gradually working 

 forward, lastly the head. When all is dry the skin should 

 be removed from the straw by careful use of some blunt in- 

 strument or the finger nail. 



A piece of wire is then taken, a little over twice the length 

 of the larva, and bent into the form shown in fig. 10, the free 

 ends being slightly incurved. A drop of shellac dissolved 



