88 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



dormant characteristics but apparently does not endow it with the 

 power of producing entirely new structures." Mr. Coseris adds that 

 the awakening of dormant characteristics "has been demonstrated 

 in the case of glands, trichomes and aeriferous tissue;" that "the 

 shape of galls is controlled partly at least by the direction of the 

 stimulus and the location of the egg of the producer. In galls 

 such as those of the Lepidopterous types, where the larva burrows 

 into the tissue after leaving the egg, this feature has no effect." 

 It was found that "the relation of the various zones in the Cynipid 

 galls is influenced in some cases by the early differentiation of the 

 cambium layer." Besides these interesting conclusions the paper 

 contains much valuable matter about the ecology of certain species 

 of gall producing insects, and deserves serious consideration from 

 entomologists as well as botanists. It is hoped that Mr. Cosens 

 will continue this valuable work so that it may eventually be pos- 

 sible to separate all the species of galls by their structure alone. 



Dr. Howard exhibited some photographs made by Mr. 

 Hodge which were shown at the Cleveland meeting of the Ameri- 

 can Association of Economic Entomologists. The pictures were of 

 a device for catching house and stable flies. Mr. Hodge has 

 devoted much of his time and energy to making a trap to catch 

 these annoying insects. Dr. Howard described the manner in 

 which these insects were captured and stated that in one trap Mr. 

 Hodge had caught 37| quarts within a short period. He also spoke 

 of another trap which was placed near a cow in which were caught 

 4 quarts, 90 per cent of which were Stomoxys calcitrans. Mr. Hodge 

 stated at that meeting that this trap was placed there for only one 

 week and would have doubtless caught more but for the fact that 

 the trap was full. 



Dr. Howard then spoke of an additional orifice near the top 

 which Mr. Hodge was placing on his latest traps which will permit 

 a larger catch. 



Mr. A. C. Morgan then read the following paper: 



