HISTORY OF LITERATURE. 23 



doubtful whether they were Hypopi or adults. This 

 interesting point was entirely cleared up by the 

 observations of the two Italian acarologists. 



Prof. R. Monier, in 1892, published a paper upon the 

 results of Wasmann's collection of Acari and Thy- 

 sanuridae in ants' nests.* It is interesting for the 

 purposes of the present work as being the first 

 announcement of Tyroglyphus Wasmanni, the only 

 species of the family at present known which appears 

 to be a true inhabitant of ants' nests, where it increases 

 to an amazing extent, the hypopial nymphs almost 

 smothering the ants. There is an error in the paper 

 as to the Hypopus, which was attributed to a different 

 species ; this error was subsequently cleared up. 



In the same year Monier published another paper,t 

 which was upon the life history of Megnin's Tyro- 

 glyphus mycophagus, which was carefully worked out ; 

 the paper also states the author's observations upon 

 the nature and development of Hypopus, in which 

 he practically repeated my own investigations on 

 the subject, but employing a different species for 

 observation, and arrived at a similar conclusion. 



In 1894 Monier contributed another important paper 

 to the literature of the Tyroglyphidas ; J it was a 

 general paper upon those species found on food and 

 drugs. The paper contains much interesting informa- 

 tion as to habitats, habits, etc., and will be found 

 frequently quoted in this book. 



J. Ligniere, in 1893, published a paper upon what 

 he called Tyroglyphus mains. This paper contains 

 a considerable amount of useful biological observations, 



* " Me moire sur quelques Acariens et Thysanoures parasites ou 

 commenseaux des fourmis," in ' Rev. biol. Nord. France/ t. iv, No. 10, 

 pp. 387-9. 



t " Contribution a 1'histoire naturelle du Tyroglyphus mycophagus," 

 'Mem. Soc. Zool. France.,' t. v, pp. 584601. 



J "Notes sur quelques especes de Tyroglyphides qui vivent aux 

 depens des matieres alimentaires et des produits pharmaceutiques," in 

 ' Rev. Biol. Nord. France, vol. vi, No. 12, pp. 442460. 



" Etude zoologique et anatomique du Tyroglyphus mains et de sa 

 nyinplie hypopial," in ' Mein. Soc. Zool. France,' t. vi, pp. 5 15. 



