33 

 31 AY nth, 1911. 



Mr. Step exhibited a teratological specimen of horse-chestnut 

 {^EsckIus kippocastaniun), consisting of a bud-scale that was longer 

 and narrower than usual and ended in seven fully developed 

 leaflets as in the typical leaf of the species, the scale itself 

 performing the function of a petiole. The opposite bud-scale was 

 developed in precisely the same manner, but these were the only 

 examples he could find on a number of young trees carefully 

 examined. For the purpose of comparison Mr. Step showed a 

 normal leaf and a normal bud-scale from the same tree. The 

 exhibit demonstrated that the bud-scale is an aborted or un- 

 developed leaf. 



Messrs. Harrison and Main exhibited a long series of Aplecta 

 nebulosa and its varieties, from Delamere Forest, and communicated 

 the following notes : — 



"The series was bred last year from robsoni xq.b\qx thorn paoni 

 female. 



" Only 60 moths were bred, 26 per cent, were of the grey form, 

 42 per cent, of the robsoni form, and 32 per cent, of the tlwinpsoni 

 form. This result quite negatives our idea that the form robsoni 

 was a heterozygote or hybrid (so-called), and that the grey 

 form and thoinpsoni were homozygotes, or pure. We had been led 

 to this conclusion by the results already reported (' Proc. S. Lond. 

 Ent. Soc.,' 1908, p. 84), obtamed by ourselves and by Mr. 

 Mansbridge (see ' Proc. S. Lond. Ent. Soc.,' 1909, p. 64). 



" From a largo brood, both parents robsoni, we bred 25 per cent, 

 grey, 51 per cent, robsoni, and 24 per cent, thoinpsoni, obviously 

 Mendelian proportions. 



" From several broods, both parents grey, we bred only the grey 

 form. 



" From grey form crossed with thoinpsoni Mr. Mansbridge 

 obtained only robsoni, and from the grey form crossed with robsoni 

 he bred 50 per cent, robsoni and 50 per cent grey. These two 

 latter broods were very small, but all the results pointed to the 

 conclusion mentioned above, and appeared to be parallel to the 

 well-known case of the Andalusian fowl, where we have also three 

 forms, a black, a white (splashed with black or blue), and a blue, 

 the latter being the hybrid, and the two former being pure. 

 However, the results obtained last year show that the problem is 

 not so simple as this, and that it will require further experiments 

 before it can be solved." 



