23 



As Buckfcon's evidence concerning the parentage of this dimorph 

 appears to be limited to (i) the accounts of others as enumerated 

 above, (ii) his personal observations on dissection of one apterous 

 female, it may be of interest to record the following observations : — 



In June of last year (1914) I segregated two of the black apterous 

 forms with a small piece of sycamore leaf, each in a separate tube. 



The following day two or three of the young dimorphic forms 

 were present, but as the tube had contained the shreds of leaf this 

 evidence was not sufficiently conclusive. 



I therefore removed the black females each to a clean empty tube 

 at 10 p.m., on Sunday, June 21st. On the following Monday 

 mornmg, at 8.80, I examined the tubes just in time to see a green 

 larva being expelled by the female. 



I was not at leisure to remain at this critical moment, but on my 

 return at mid-day the VeriphyllHn (or dimorphic) form was there 

 fully developed. The following day, Tuesday, at 8.17 p.m., I had 

 the pleasure of seeing the same black female in the act of bringing 

 forth another green larva, the whole of which, except the head, had 

 been extruded. 



The margins of the body were folded downwards, so that a trans- 

 verse section of the abdomen would have exhibited a curve nearly 

 semicircular. 



There was nothing to be seen from above of legs, antennae, or 

 any of the peripheral leaflets. 



By 8.26 three of the folioles were perceptible. A minute later 

 the antennas were free. 



At 8.28 all the abdominal folioles could be discerned ; the legs 

 appeared and were in motion. 



There was al.-o a slight extension of some organ from the anal 

 region, and the whole of the body was flattening out. 



By 8.34 the head was liberated and the birth was complete. 



The mother immediately walked away, leaving her extraordinary 

 offspring to its fate. 



At 8 p.m. on the following Thursday the same tube contained 

 eight young, all of them of the pseudomorphic variety. 



The other isolated female also produced several larvje of the 

 same kind. 



The problem relating to the use to the species of this abnormal 

 larva, which, so far as seems to be known at present, performs no 

 other function than thiit of feeding, remains unsolved. 



It is, however, difficult to believe that nature should produce, in 

 such abundance, a creature that completes its existence without 

 being of any service whatever to its kind. 



The following are notes on some observations made subsequently 

 to the reading of the Paper: — 



(1) On June 24th Mr. W. West, of Ashtead, kindly furnished me 

 with some leaves of Acer negundo (Box-elder). 



