796 



THE AMEBIC AN NATURALIST [Vol. XLII 



seared by means of a heated needle. These specimens 

 were then placed on a plant and, although badly treated 

 by the operation, soon found suitable places and began 

 to suck up the juices, and as usual became enlarged. In 

 the majority of cases each nymph began to emit drops of 

 fluid from the anal opening. Although during the emis- 

 sion of this fluid the caudal segments of the abdomen were 

 extended and retracted as in the normal specimen, in no 

 case were bubbles formed within the secretion. This was 

 true even after twelve to fourteen hours. In order to 

 test whether this was due to the lack of some constit- 

 uent normally secreted by the injured glands, air was 

 blown into the fluid through a finely pointed tube; in- 

 stead of being retained, none of the air balls remained 

 in the fluid more than five to ten seconds. On the other 

 hand, bubbles blown into the secretion of unseared speci- 

 mens held in it for a very long time. This experiment 

 was repeated many times over and always with the same 

 result. 



Other Supposed Sources of the Secretion 

 Besides these glands, other structures have been men- 

 tioned as participating in the formation of the froth, and 

 in order to determine what part they played in it they 

 were given careful consideration. 



Berlese (1907) regards the glands of Batelli as the 

 sole source of the secretion. This, my observations, con- 

 firming in part those of Morse and others, have shown 

 conclusively to be incorrect. While I hold that the above- 

 mentioned glands contribute an important element to the 

 spittle, there is not the slightest question but that the 

 fluid portion is emitted from the anal opening. 



We have seen that Porta (1900) considered the secre- 

 tion as formed primarily by glands scattered among the 

 hypodermal cells of the abdomen and opening to the 

 surface through prominent canals, and that these were 

 especially abundant in the region of the stigmata. All 

 that could be noticed were the openings of trichopores. 



