2IO CHARLES W. HARGITT. 



showed that in no case of his numerous dissections, more than 

 two hundred in all, of either nymph or adults, did he find traces 

 in this organ of undigested food. 



All this is abundantly confirmed by my own later work as it 

 in turn also confirms earlier observations as to the feeding habits 

 of these insects. Likewise, this is found borne out by the micro- 

 scopic sections of the canal through every region of the mature 

 insect by the junior author as shown in his previous paper. But 

 there are certain rather puzzling features in this particular organ 

 in adult life. It does not appear clear that its increase in size at 

 this time can be due to a reservoir function, unless feeding be 

 increasingly active during later life, which certainly does not 

 seem to be the case. Again such a view seems to be in direct 

 conflict with the histological character of the organ which shows 

 clear evidence of degenerative changes in its lining epithelium. 

 On the other hand it seems to conform with the view just pre- 

 viously expressed that it is during this stage apparently function- 

 less in any active way, and that as the storage elements are 

 resorbed the organ reacts in consequence, its walls expand to 

 occupy the visceral spaces which earlier were filled by storage 

 matter and reproductive organs, which in turn accounts for the 

 attenuated condition of the epithelium described by Hickernell 

 as above stated. 



A further fact in this connection remains to be noted, namely, 

 that these adult insects leave no signs of excretory wastes, such 

 as defecative products. The writer has handled living specimens 

 by hundreds, taken at various times, some kept under bell jars, 

 others in clean breeding cages, as well as others still which were 

 freely handled, but has not seen at any time evidence of defeca- 

 tion. Of course, the liquid sap upon which these insects feed 

 might, and doubtless does show less of solid waste to be dis- 

 charged, but certainly there are unused elements even in such 

 foods as sap which doubtless are extruded ; as are those heavier 

 products whose wastes are so conspicuous in the life surroundings 

 of most feeding insects. The well-defined and thick-walled 

 rectum of the cicada goes to support this view. This point is 

 made as a matter of fact which should not be overlooked; but 

 so far as I am aware it has not been given attention heretofore. 

 Were feeding at all frequent or general in the adults such solid 



