336 ARACHNOIDEA, 



CASE the best authorities are very instructive, and the reader will there- 

 fore excuse our going a little into detail regarding it. 



*M. Duges, then, the first authority of the time upon mites, 

 remarked in two papers upon M. Turpin's discovery. In his first 

 observations, he mentions that M. Turpin's drawings were un- 

 fortunately not pubHshed, and he only knew his descriptions from 

 insufficient extracts ; but, from some verbal explanations which 

 he had received from him, he had learned that it was not by a 

 complete analysis of the mouth that this distinguished naturalist 

 had formed his diagnosis, which besides, even although made, 

 must still have been very uncertain. M. Duges had then himself 

 set to work to find M. Turpin's mite, but failed, altho' he met with 

 some Tetranychus teliarius laying their eggs at the very door or 

 entrance of the galls \ and he then suggests that it may have been 

 its offspring that M. Turpin had seen, acknowledging at the same 

 time that M. Geoffrey St. Hilaire, who had seen M. Turpin's 

 drawings, could find no identity between it and the specimens of 

 Tetranychus teliarius shown him by M Duges. 



Not long aftenvards, however, M. Duges was more successful in 

 his search. Abundant rains had fallen, and he profited by the 

 first fine days in searching on the black poplar for the galls said 

 to occur on it, and he found some on the white willow, but not 

 on the poplar. These were smaller, rounder than those of the 

 lime; green or reddish, and covered with down outside : they pro- 

 ject on the upper and under side of the leaf, but more on the 

 upper side. Like those of the lime, they open un> erneath by a 

 hole, which is obstructed by the villose filaments which are 

 found inside. In the interior, however, these filaments were less 

 abundant ; and there he easily found, in great numbers, the mites 

 of M. Turpin. He again searched and found them also in the galls 

 of the lime. As to the more advanced galls, he found the walls 

 often quite covered with these supposed Sarcoptes : they were 

 very small, whitish, vermiform; and, as he supposed, very probably 

 one of those which Reaumur speaks of having noticed, and which 



