HISTORY OF LITERATURE. 19 



A. D. Michael. In 1879 the first of my own papers 

 containing matter relative to the Tyroglyphidas 

 appeared.* This was a short and somewhat popular 

 paper dealing chiefly with facts already known, but it 

 is of some importance as being the first time when it 

 was pointed out that the posterior projection of the 

 female Glycyphagus was a bursa copulatrix, a fact 

 which I had discovered from actual observation. 



In 1884 a paper of my own appeared, t dealing with 

 the vexed question of what a Hypopus really is, and 

 the circumstances and conditions which favoured or 

 discouraged its production. The paper was the result 

 of a long series of observations of Tyroglyphidge, both 

 in confinement and in their natural habitats. I believe 

 that it is now generally admitted that the conclusions 

 arrived at are correct. The hypopial stage is pro- 

 bably the most interesting thing connected with the 

 Tyroglyphidge, being quite exceptional in nature ; there- 

 fore it is necessary that the facts recorded in this paper 

 should be fully stated in the chapter of this work rela- 

 tive to the immature stages, for which reason it is not 

 necessary to occupy space here by abstracting it. 



In 1885 appeared another paper of my own J upon 

 Histiogaster corticalis. In it the life-history of the 

 species which had not been known previously is 

 worked out, and a certain confusion of species I had 

 hoped made clear; but some subsequent writers have 

 continued the old errors, which will be again explained 

 in this book when treating of the species. The paper 

 also contains a further contribution to the literature of 

 Hypopus, being chiefly further proofs of the correctness 

 of the last-mentioned paper; also a description of the 

 Hypopus of Rhizogtyphus echinopus (Robini). 



* " On some Peculiarities in the ^Reproductive System of certain of 

 the Acarina," in ' J. Quekett Club,' 1879, vol. v, pp. 223230. 



t " The Hypopus Question, or the Life-history of certain Acarina," 

 in ' J. Linn. Soc., Zool.,' vol. xvii, pp. 371394. 



J " Notes on the Life-history of some little-known Tyroglyphidse," 

 in ' J. E. Micr. Soc.,' ser. 2, vol. v, pp. 1932. 



