1SG4.] 589 



racters specified in the description, as well as by its average size being 

 just double. One of the above 4 galls had the heart eaten out by some 

 lepidopterous larva; and adhering to the leaves of another was the 

 pupal integument of a Lepidopteron, much larger than any of those 

 commonly bred by me from the allied galls. All of them, as is very 

 generally the case in this group of galls, had many of their leaves eaten 

 into by Lepidoptera. and contained much Lepidopterous "frass" or 

 excrement. 



I know but three Willow-bushes near Rock Island which can be re- 

 ferred to S. discolor. One of them, a $ . of which I forwarded to Mr. 

 Bebb the inflorescence, was pronounced by him to be certainly S. dis- 

 color ; it was from this one that I obtained the galls, which for the 

 present I refer to S. batatas and S. siliqiia. Of the second, also a $ , 

 I forwarded nothing but the fruit, and Mr. Bebb referred it doubtingly 

 to S. discolor, but thought it might possibly be S. eriocephala. I have 

 carefully compared foliage, twig and bud in these two, and have little 

 doubt they are identical. At all events their very robust, vigorous 

 twigs, tinged with purple and covered with whitish pulveruiescence, so 

 as strongly to recal those of many varieties of apple-tree, and the large 

 buds which have commenced opening out even as early as the last of 

 November, effectually distinguish both, even in the winter time, from 

 the 4 other species of Willow found near Rock Island. The third 

 bush was not discovered by me till the last of November, and agrees 

 so perfectly in all the above characters with the one which is undoubt- 

 edly S. discolor, as well as in the foliage, some of which still adhered 

 to its twigs, that I have little hesitation in referring it to the same 

 species. I observed however on its main limbs large blotches or wide 

 bands of whitish-gray, which could not be seen on either of the other 

 bushes. In any case the inflorescence next spring will definitively decide 

 the question of its specific identity with S. discolor. It was on this 

 last that I found the galls C. co/yloides ; the second bush bore no galls 

 at all. 



It thus appears that of the 5 willows growing near Rock Island, four 

 have galls all constructed on the same fundamental principle out of 

 deformed buds, and one of them — S. humilis — has two such galls. It 

 is a remarkable and suggestive fact, that the remaining willow has no 

 such galls nor anything approaching to them. In numberless localities 



