3540 The Zoologist— May, 1873. 



have as yet been found only in the female sex, will be found to be double- 

 brooded species, one of which will be exclusively female and the other male 

 and female. 



" I have two or three years tried to raise a colony of C. q.-puuctata, 

 Bassett, by placing the large poly thalamous galls on uninfected trees j ust as 

 the insects were ready to escape. So far I have failed to rear any galls of this 

 species. Now if these females really reproduce the same kind of gall 

 I ought to have succeeded, for I colonized several hundred individuals on a 

 single small tree, and many more on other trees in different seasons. Of 

 course the inference to be drawn from the failure of my attempt to raise 

 these galls has no scientific value, but had I succeeded in raising the galls 

 the fact would have been received as satisfactory proof that these female 

 flies could produce generation after generation of females without the aid of 

 the male clement. 



" I take the ground that the reproduction of gall-insects without the inter- 

 vention of the male is limited to a very few, if not even to one generation ; 

 and that all our unisexual species are dimorphic forms of double-gendered 

 species. I wish yourself and all others interested in working out the 

 singular history of this family would give attention to these points. 

 And may I ask you to inform me if anything has been written within a 

 year or two that throws any light upon them, as I am aware that my non- 

 intercourse with the entomologic world for a year or two past has left me 

 far behind possibly on this very point. 



" I was able last spring to settle, to my own satisfaction at least, a question 

 raised by myself in the first article I pubhshed on the Cynipidte, — the ques- 

 tion whether the woolly galls, C. q.-seminator, Harris, and C. q.-operator, 

 Osten-Sacken, were or were not abnormally developed leaves. I took the 

 ground that they were, that the eggs were deposited in the oak-bud, that 

 the small seed-hke gall was only a modified leaf-stem and blade, and that the 

 wool was only an enormous development of the pubescence always present on 

 the young leaves. Mr. B. D. Walsh opposed this idea, and, either in a pub- 

 lished paper or in a letter to me, denied that the gall had any connexion 

 whatever with the bud or leaves. Last spring I was so fortunate as to find 

 two galls of C. q.-seminator in their earliest stage, and was able to watch 

 them in their development. They are really developed from buds, and are, 

 as I supposed, only modified lea%-es. The smooth shining cell or gall is the 

 petiole of the leaf, and the tuft of long woolly hairs that terminates the cell 

 is only the enormous development of the leaf's pubescence." 



Kew Part of ' Transactions.' 

 Part I. of the ' Transactions ' for 1873 was on the table. — F. G. 



