﻿116 Journal New York Ent. Soc. [Voi. hi. 



Candeze thinks the fluid may contain prussic acid. The fluid is se- 

 creted by a variable number of glandular cells, each provided with an 

 efferent duct. The larvae of sawflies, notably Cimbex americana, also 

 eject droplets of a clear fluid from their skin. 



In this connection it may be mentioned that though there are no 

 special glands present, many beetles emit drops of blood from the fe- 

 moro-tibial joints of their legs as a means of defence. Such are the oil 

 beetles (^Meloe), Canthaj'is, Lytta. The cantharadine secreted by these 

 beetles, according to Beauregard, is an efficient means of defense 

 as birds, reptiles and carnivorous insects will not usually attack them. 

 This substance is formed in the blood and also in the genital organs, and 

 is so extremely caustic that scavenger insects which feed upon their dead 

 bodies will leave untouched the parts containing cantharadine, and if 

 May-beetles or Mole Crickets are washed with the blood of Meloe or 

 with cantharidate of potassa, it will for several days render them safe 

 from the attacks of the carabids which usually prey upon them. The 

 eggs even after deposition are strongly vesicant, and are thus free from 

 the attacks of egg-eating insects (Cuenot). The Coccinellidse are also 

 protected by a yellow mucilaginous disagreeable fluid oozing out of the 

 sides of the thorax; in our common two-spotted Lady-bird (C bipiinc- 

 tatd) the yellow fluid is disagreeable, smelling like opium.* 



The Dytiscidas eject from the anus a colorless disagreeable fluid, 

 while these beetles, and especially the Gyrinid^e, when captured send 

 out a milky fluid which appears to issue from the joints of the body. 

 The Silphidae throw out both from the mouth and vent a fcetid liquid 

 with an ammonial odor. They possess but a single anal gland, the 

 reservoir opening on one side of the rectum (Dufour). 



More agreeable secretions, but probably formed by similar glands, 

 is the odor of rose or hyacinth given out by Cicindelai, or the rose 

 fragrance exhaled by the European Aromia moschata. 



Other malodorous insects have not yet been investigated ; such are 

 the very persistent odors of lace-winged flies (^Chrysopa). 



The anal glands consist, accordmg to Meckel and also Dufour, of 

 two long simple flexuous cceca with reservoirs having two short excretory 

 ducts situated near the anus (Siebold). 



Many caterpillars, as our subjoined list will show, are very well 

 protected by eversible repugnatorial glands situated either in the under 

 or upper side of the body. Since the time of DeGeer (1750) the fork- 



* Lutz has found that the blood in Coccinellidre passes out through a minute 

 opening situated at the end of each femur. (Zool. Anzeiger, June 24, 1895.) 



