THE SOCIETY*S NOTE-BOOKS. lOl 



Murray's " Handbook " on the Aptera is to be depended on, have 

 not hitherto been found in England. 



HoplopJiora is one of the known Enghsh genera. One species 

 of it Uves in decaying Fir-wood ; another on the roots of the 

 Vine. 



The following account, gathered from the above-named work, 

 appears sufficiently interesting to be introduced here : — Clapa- 

 rede found H. contradilis in the burrows or borings in rotten fir- 

 wood ; but he sometimes found with it another larger, semi- 

 transparent, soft, white mite, like a Cheese-Mite. One might 

 naturally think that this was possibly the larva ; but then it had 

 eight legs, and therefore it was assumed that it must be in its 

 mature state ; moreover, by watching the eggs deposited by 

 Hoplophora, Claparede soon ascertained that, as usual, the first 

 stage was a six-footed, soft, white mite, bearing a close resem- 

 blance to the eight-footed soft, white, Acaroid form. What 

 relation did the latter bear, then, to the Hoplophora with which 

 it was associated ? M. Claparede solved this by the following 

 experiment : — He took twenty specimens of the soft, white, 

 Acaroid Mite, and placed them on a morsel of decaying pine- 

 wood, first making sure that there were no other mites present. 

 After keeping the wood for three weeks in a moist flask, the Mites 

 were scarcely to be seen. They had bored into the wood, and 

 had to be dug out. On examination, he found only twelve speci- 

 mens resembling Acarus against seven of Hoplophora. A 

 transformation of seven had thus taken place, and one individual 

 was missing. But the nature of the transformation was not yet 

 clear. He repeated the experiments, and followed the traces of 

 the transformation. He found that a perfectly colourless Hoplo- 

 phora was developed inside the Acarus-like form. Those Acaroids 

 which were becoming Hoplophorse appeared very light to the eye. 

 The perfect animal leaves the larval skin with its parts pecuharly 

 tender. It then lies for a long time seemingly immoveable ; 

 but by degrees the coat thickens and becomes firm. From being 

 colourless it turns rose colour, then reddish, and at last quite 

 brown. An important point, however, remained doubtful. In all 

 his experiments, several Acari, and these the largest specimens, did 

 not change ; how are these individuals to be looked upon ? Per- 

 haps as males. It is very striking that he did not find in 

 Hoplophora any difference of sex, and that most specimens 

 contained eggs. Nor could he, with any certainty, discover any- 

 thing distinctive of the male sex. The important fact ascertained 

 by M. Claparede is that the Hoplophora goes through an Acarus- 

 like, soft stage, which proves its relationship to the real Acarids 

 (Cheese-Mites, etc.) 



