338 ARACHNOIDEA. 



^SE in the family of the Trombidiidae, near Tetranychus ; or again 

 the number of feet would prove that it was only a larva and 

 not a perfect mite, because there were only two pairs, and the 

 other larvae have usually one more. But if that were so whence 

 came the eggs that were also found in the galls? He felt no 

 doubt that they were deposited by adult individuals, who had 

 come there to lay their eggs. The free entrance to these galls 

 would allow them to come in, just as it would allow insects 

 newly arrived at maturity to go out. The latter point he proved 

 by the following facts : — first, that many of these little beings 

 were seen to become motionless, changed into elongated pupas, 

 in which the body was already seen to contract, abandoning the 

 extremities of its cutaneous case ; secondly, two or three times 

 small mites with eight feet had been seen in the galls, white, 

 short and agile, having all the characteristics (palpi and feet) of 

 Tetranychus. Now and then, these little things resembled per- 

 fectly the larger reddish Tetranychus, which had been found 

 several times in the large galls. These Tetranychus were not at 

 all of the same species as those on the lime, which live on the 

 back of the same leaves with their eggs and young. They were 

 of a much smaller shape, and differed in some details of form and 

 in the greenish colour of the one, and light red of the other. 



In conclusion he acknowledges that a good deal of doubt rests 

 upon the supposed affinities either with Sarcoptes or Tetranychus ; 

 and even upon the share they have in the production of the galls 

 they live in. 



Along with these remarks M. Duges gave a figure of the mite 

 he found, which quite corresponds with those of subsequent 

 authors. 



The next step was made by M. Dujardin, in 185 1, when he 

 also detected the same mites in the nail-gall of the lime-leaf, and 

 published an account of them with a figure more highly magnified 

 than that of M. Duges. Under higher power, the body of the 

 mite is seen to be transversely striated -, but it is time that the 



