414 ENTOMOLOGICAL NEWS [Nov., 'lO 



ing these jaws to the body wall are joined ; to this is hinged 

 a much smaller and more cylindrical portion to the knobs of 

 which the jaws proper are fastened; these are made up of 

 three joints, each capable of being" moved in the other and 

 the terminal one with a very sharp point : these points if 

 brought together rapidly and forcibly, can tear away any sub- 

 stance capable of mastication by such small animals. These 

 jaws are so strongly attached to the larva that they cannot 

 be pulled out, but must be cut away from the body-wall, and 

 yet may be retracted by the maggot. 



From this mouth extends quite a simple alimentary tract 

 consisting of a long tube with three enlargments : a crop, a 

 stomach and the proventriculus, at the base of which enter 

 five tubes; these are the malpigian tubes and they probably 

 perform an excretory function. This whole tract is trans- 

 parent, except the stomach, which has very muscular walls, 

 is absolutely opaque, and of a yellowish-orange color ; the 

 outer part of the tube is perfectly clear throughout its whole 

 length, while the inner portion is mottled, seems to have par- 

 ticles of food in it, and to be a tube within a tube. The only 

 reason that can be given for this is that this contraction took 

 place after death, and was due to the chloroform, but as in- 

 sects do not breathe but through the tracheae this does not 

 seem a plausible explanation. 



These larvae are full-grown at the end of five days, and 

 are then about one-half of an inch long. As soon as they have 

 attained their growth, they stop eating and begin to burrow 

 into the ground. They do not all reach this stage at exactly 

 the same time, it being not less than three days before all 

 the maggots had disappeared from view. If they are not al- 

 lowed to go into the earth, they will try to burrow into any- 

 thing that is soft enough, or if there is nothing to hide in, 

 they simply become quiet and grow shorter and more rotund. 

 However, larvae in this state will move on stimulation for at 

 least two days after the quiescent period has commenced. On 

 removing them after one day under ground, it will be noticed 



