GALL MITES. 345 



ASE mite, an ^gg just ready to be protruded accompanied by one 01 

 two others in a state of progression, on which Professor Westwood 

 suggests that this may be one of those cases in which the ordinary 

 proceedings of insect life are departed from. " Parthenogenesis," 

 says he, " or the production of offspring by a virgin or unmatured 

 female, has been already observed among the Acaridae, and we 

 now know that the young larvae of certain Cecidomyse, or gall 

 midges, are capable of producing fertile eggs, whilst others 

 of the same larvae are transformed in the usual manner into 

 midges. Is it possible that this is a similar case of larval pre- 

 cocity ? If, on the other hand, the creature produces eggs as a 

 normal condition of its existence, we have here the case of a 

 perfect Acaridan never assuming more than two pairs of legs, and 

 which would require for its reception, not only a distinct generic 

 name, but a distinct family of mites." 



The latest contributor to our knowledge of the Phytopti is Dr. 

 Franz Low, who, in 1874, in the " Verhand. Zool. Bot. Gesells., in 

 Wien," has published two important papers, giving an account of 

 many mite-galls and their producers. He gives a figure of Phy- 

 toptus (part of which we here reproduce), in which, in place of the 

 four stumps of feet that V. Landois thought he saw, there are seen 

 four bristles springing from four warts, and he argues that it was 

 by some displacement or ocular illusion proceeding from them, 

 that V. Landois was deceived (if he was deceived). For our- 

 selves we rather think that he was not, and that the difference 

 between the observations of Landois and F. Low is one of words 

 rather than reality. V. Landois's four stumps of legs are doubt- 

 less F. Low's four warts, which he regards as the homologues 

 of legs. 



These are the main circumstances connected with the past history 

 of the Phytopti so far as we know them, but it is right to .,say that 

 there may be others which have escaped us. Kaltenbach, in his 

 Pflanzenfeinde, makes frequent reference to Dr. Amerling, of 

 Prague, and Dr. Kirchner, of Taplitz, two Hungarian naturalists, as 



