Vol. xxi] i:\io.MOLor.iCALNE\v.s 413 



is certainly very complete. The posterior end of the body 

 is nearly circular and here the tracheae terminate in two spir- 

 acles, and at the second segment on the ventral side they end 

 in two fan-like projections, which in the blow-fly Lowne says 

 are functionless, which may be the case in this maggot also. 



The larvae grow rapidly ; the warmer the weather the 

 faster they grow, and when full-grown are nearly opaque 

 and very strong. Their integument is very tough and thick 

 and nothing seems to kill them but sunshine, drought, chloro- 

 form, and boiling \vater poured over them. They will not 

 live more than two or three hours if left unprotected from 

 the direct rays of the summer sunshine and will raise a heavy 

 weight for such a small being in order to get into the shade; 

 and in all stages of their development, lack of moisture will 

 cause death. Several larvae and all of the pupae brought into 

 the house died, and the second summer, when there was no 

 rain for three weeks, but three flies appeared, in spite of the 

 fact that they had been wet with water from the hose. It is 

 even difficult to produce death by means of drugs ; one larva 

 placed in a cyanide bottle that had killed several insects was 

 found the next morning burrowing in the plaster of Paris in 

 the bottom of the bottle ; it was then put into alcohol and 

 after ten minutes w r as found standing upright on its anterior 

 end or head ; on another, benzine was poured and ammonia 

 tried without result. But boiling water poured over them or 

 the fumes of chloroform will cause death in a few minutes. 

 It is to be inferred that their skins must be kept moist or they 

 would not suffer so from lack of rain and from direct heat, 

 and also that they do not take in a great deal of air, or fumes 

 would have a deadlier effect on them; thus the toughness of 

 their integument keeps them from being easily killed. Their 

 jaws are so powerful that a full-grown larva moving across 

 your hand will feel like a series of slight pin pricks, and 

 they can make a scratch on a piece of cardboard. 



A full-grown larva consists of three parts : a basal por- 

 tion like a rounded plate, to which the strong muscles attach- 



