LIPK-HISroKIES OF SAWFLIKS. 277 



On the 5th of September, 1869, 1 took home some galls on 

 leaves of the first-named species of willow, which is here the 

 commoner. 1 carefully cut one of the smallest into three 

 pieces, and found in it a greenish white larva, scarcely one 

 millimetre long. It appeared to me to have twenty legs; 

 the head was black, and the body wrinkled. The gall was 

 so grown together that there was hardly room lor the little 

 animal; fig. 3 was drawn from this specimen. It speaks for 

 itself that this larva soon died. The remaining galls dried 

 up, and 1 determined to look for others. However, the 

 matter was put off; and the winter came without my having 

 made any further observations. 



On the 31st of August of the following year 1 came across 

 a clump of the red willow on the downs near Noordwijk, 

 having almost all the leaves covered with large pear-shaped 

 galls projecting from either surface: they were pretty well 

 double the size of those of the white willow. I could see 

 that some of the inhabitants had already left their dwellings, 

 as in some cases a little round hole was visible in the gall ; 

 fig. 2 represents one of these galls. The larvae which I found 

 in them differed much in size and age; the larger number, 

 however, were full grown, and these were of the size of fig. 4, 

 that is to say nine millimetres in length. One of these, magni- 

 fied, is shown at fig. 5. The head was shining black ; the 

 body brownish yellow, in some cases with a greenish tinge; 

 in others the head was gray, with black marks on the legs, 

 and having the body more of a gray colour, with a red tinge 

 in the middle, especially on the back. There were in all 

 twenty feet. 



This account of the larva differs from the description 

 given by Svvammerdam and others, in this — that the later 

 observers describe the full-grown larva as being more green 

 than the young ones, while with me the more advanced 

 larvae were yellower, or more of a nut-colour. 



1 placed the willow leaves, which I had collected, in a 

 confectioner's glass, with some mould at the bottom ; I had 

 not been able to bring home any whole branches. This 

 prevented my having the opportunity of observing whether 

 the larvae, as is stated of the described species, bite a hole in 

 the gall when the latter has become filled with excreta, and 

 protrude the anus through the hole for the purpose of 



