IXODIM: 493 



the human body we know from the following cases out of many 

 recorded : Geber observed that the Dermanyssus had caused a diffused 

 eczema on a woman, which lasted four weeks and then disappeared. 

 The tiqne of F. V. Raspail is the bird Dermanyssus ; he records 

 children and adults being attacked not only when handling pigeons, 

 but even when walking in a garden manured with pigeons' dung. 

 The affection soon disappeared when the pigeons were destroyed and 

 the excreta buried. I have frequently heard of poultrymen being 

 seriously attacked by this pest. F. V. T.] 



Genus. Holothyrus. 

 Holothyrus coccinella, Gervais, 1842. 



Measures 5 mm. in size ; lives on birds in the Island of Mauritius ; 

 ducks and geese frequently fall victims to its bite ; it also attacks 

 human beings, on \vhose skin it causes severe burning and swelling, 

 but no reddening ; it may be dangerous to children, especially by 

 settling in the oral cavity. 



Other Gamasides occasionally occur in man, for instance, according to Moniez, 

 Leignathus sylviarum, Canestr. et Fanzago ; according to Neumann Lcelaps stabularis. 

 The former live normally in the nests of various species of Sylvia, Laelaps on dried 

 vegetable substances, also in houses. 



[Marchoux and Conoy (Bull. Soc. Path, exot., 1912, v, No. 10, 

 pp. 796-798) found Leishman granules in Lcelaps echidninus. It is 

 assumed that Leishman granules may be found in most Arachnoids, 

 and have no connection with Spirochaeta. F. V. T.] 



Family. Ixodidae (Ticks). 



Comparatively large Acarines with a leathery skin ; they are flattened in form, 

 but after sucking blood the abdomen becomes spherical ; the chelicerae are rod-like 

 and possess a serrated terminal joint, bent hook-like ; the median parts of the 

 pedipalpi (maxillae) form a rostrum furnished with barbed hooks (fig. 359) ; the 

 maxillary palpi themselves are club-like or rounded ; the legs are composed of six 

 segments with two terminal ungues, often also with u sucking discs " ; the stigmata 

 are at the sides of the body, posterior to the fourth or third pair of legs. The larvae 

 are six-legged. 



[The true ticks (Ixodida) are all blood-suckers, and as far as is 

 known they do not take vegetable food at all. Not only are the 

 Ixodidcv important as actual parasites, but they are most so on 

 account of the fact that they are the active agents in carrying various 

 diseases in animals and apparently in man. It has been conclu- 

 sively proved that the bont tick (Amblyomma hebrcenni) is the carrier 

 of the fatal " heart-water fever" so rife amongst sheep in South 

 Africa, that the dog lick (Hcemaphy salts leachi] is the agent by which the 

 protozoa that cause malignant jaundice in dogs are distributed, that 



