72 



is provided with two recurved hooks which strengthen the con- 

 nection during the act of copulation. Indeed, it is not uncom- 

 mon for the female to be seen dragging about the dead body of 

 the male still fastened to her by these hooks. As the locusts 

 appear in about the same numbers at every period of their return, 

 it follows that only two of the eggs on the average are developed. 

 It would thus appear, supposing the production of these insects to 

 have always followed the same law, that there must have been 

 originally a multiplicity of individuals. The male is about one 

 third larger than the female. 



The drumming apparatus of the male, Dr. Burnett had made 

 the subject of careful microscopic study. He had found it to be 

 integumental in its nature, not presenting any relation either by 

 structure or analogy to the respiratory system. It is situated on 

 each side, between the thorax and abdomen, the head of the 

 drum being just under the attachment of the wings to the body, 

 and of the size of a marrow-fat pea. It consists of a tense, dry, 

 crisp membrane, crossed by cords or bars, produced by a thicken- 

 ing of the membrane, which meet on one side at the point of 

 attachment of the muscles, which by their contraction keep it 

 stretched. The sound is produced by a series of rapid undula- 

 tions, running from the contracting muscles across the drum. 

 The upper part of the abdomen seemed to serve as a sort of 

 sounding-board ; when a portion is removed the sound is sen- 

 sibly diminished. A dry condition seems to be necessary to the 

 perfect action of the drum, as on wet days, or when it is moist- 

 ened, the sound is very much diminished. The drumming sound 

 is heard four or five hours during the heat of the day, principally 

 between the hours of twelve and two. In the female there is no 

 drum, nor any trace of the muscular apparatus belonging to it. 

 As an illustration of the immense numbers in which these insects 

 appear. Dr. Burnett stated that he saw an oak tree on every leaf 

 of which were six or eight individuals. 



In reply to a question from Mr. Ayres as to the charac- 

 ter of the oral circle of the Cucumaria, described by him at 

 the last meeting, Mr. Stimpson said that it was composed 

 of pieces arranged, in the words of Mr. Ayres's illustration, 

 "much like the teeth of some species of sharks." 



