172 ENTOMOLOGICAL SOCIETY 



penetrated the walls of the cocoon and from the inside had been 

 covered up with a new lining of silk by the larva in order to 

 prevent moulding or the access of moisture from the surround 

 ing earth. But a more careful examination shows them to be 

 too perfectly tubular and too uniform to fully justify this ex 

 planation, and I am forced to the conclusion that they are made 

 purposely by the larva, doubtless by the labium, and that they 

 are intended for some special purpose, possible of ventilation 

 and respiration. This hypothesis brings up the interesting 

 general question, so far as it relates to insects, of the need of 

 ventilation in the cocoons or other protective retreats in which 

 they hibernate and undergo their transformations. It is a most 

 interesting question, which I cannot discuss at length in this 

 connection. 



Mr. Mann stated in the discussion of this paper that Trouve- 

 lot had tried the experiment of shellacking the cocoon of Bom- 

 bycids without any difficulty in breeding therefrom. General 

 discussion followed on the breathing of larvae and pupae espe 

 cially in the case of sub-aquatic Coleoptera. 



Mr. Fernow presented a paper on Psilura monacha, of which 

 he has furnished the following abstract : 



THE RAVAGES OF LIPARIS (PSILURA) MONACHA IN 

 GERMANY AND MEANS OF DEFENSE.* 



BY B. B. FKRNOW. 



[AUTHOR'S ABSTRACT.] 



Mr. Fernow spoke of the alarming increase of Liparis mona 

 cha in Germany, and especially Bavaria, during the last year, 

 and the anticipations of still greater damage in 1892, and hence 

 the diligent search after effectual remedies. He pointed out 

 that such ravages in German pine and spruce forests meant not 

 only many thousands of dollars loss in depreciation of wood 

 values, but also most inconvenient disarrangement of working 

 plans, which are necessarily laid for 100 or more years in ad 

 vance. He brought forward further statistics to show the 

 significance of the pest, and then described such life habits as 



*See Insect Life, Vol. Ill, pp. 379-82, for full author's abstract of this 

 article. 



