82 fApril, 



water (by ciulosuiosis ?) when iuimersed, and swell up very much, 

 they may recover (in some species only ?) after this has made some 

 progress.) I took it out and left it out two hours, it was then quite 

 active and seemed normal ; I then re-immersed it. 



The next day, the 24th, after twenty-four hours' immersion, it 

 seemed quite well ; on the 25th (forty-eight hours under water), it 

 seemed quite lively ; 26th, still quite active after seventy-two hours' 

 continuous immersion. On the 27th, ninety-six hours' immersion, is 

 rather distended, and apparently dead ; removed it from the water, 

 and in ninety minutes after it had shrunk perceptibly, and moved 

 when touched. On the 28th, after being out of the water twenty- 

 four hours, it seemed quite well and active, but after twenty-two hours 

 re-immersion it appeared to be dead, and though removed from the 

 water did not recover. I imagine removal from its food plant had 

 more to do with killing it than the immersion. 



I have not since had an opportunity of experimenting with any 

 internal-feeding larva to test the question, but it seems probable that 

 the possibility of being overwhelmed by sap or other moisture in 

 its burrow, has been provided against by this great power of resistance 

 to drowning, to which most Lepidopterous larvae rapidly succumb. 



Betula, Eeigate : 



March, 1904. 



THE PREPARATORY STAGES OF ABICELLA FILICORNIS, Pictet. 

 BY KENNETH J. MORTON, F.E.S. 



A good many years ago I published in this Magazine (1890) 

 details of the earlier stages of the less typical species of Leptoceridce, 

 intending to deal with other genera later, but circumstances at the 

 time prevented me from carrying out my plans. In the meantime, 

 the work has been taken up by other hands who have dealt with it 

 more thoroughly than I should have been able ever to do. None of the 

 vigorous workers in this field seem, however, to have met with this 

 Adicella, and it is desirable therefore that what I have noted down 

 concerning the larva, nymph and case should not be lost. Although 

 I have not now the material available to enable me to revise what I 

 had written so long ago, the details are, 1 think, on the whole, 

 accurate. 



The species was known to Pictet even in its larval state, and he 

 gives a very good figure of the larva and case. His descriptions are, 

 however, hardly adequate for present day requirements. The insect 



