AKACHNIDA 267 



accidental, so to speak. Of the former kind, perhaps we may 

 reckon the two species discovered by Hessling (Ccelognathus 

 morsitans and Entarsus cancriformis) . Of the latter sort, those 

 found by Busk, Simon, and Bory de St Vincent may be cited. 

 The mite found in Simon's case was the Dermanyssus avium, 

 which infests cage-birds. Probably it was the same species 

 which Bory found on a lady ; but in Busk's negro sailor the 

 mite may have been D. gallince of the common fowl. Differ- 

 ing from the mites, proper, and also from the true ticks, are 

 some bug-like forms called Argades. The two best known are 

 the Miana bug of Persia (Aryas persicus) and the Chinche of 

 Columbia (A. chinche). Like their congener infesting pigeons 

 * (A. reflexus) these parasites are terrible blood-suckers. The 

 bite of the Persian bug is so venomous as to have occasioned 

 death. Various species of tick have been known to attack man, 

 but the species have not been well determined. Although a 

 human form has been described (Ixodes hominis, Koch), yet it 

 is more probable that the species usually attacking man are the 

 same as those known to infest the domesticated animals. In 

 this list we may, therefore, reckon Ixodes nigra, Ix. bovis, Ix. 

 ricinus, and Ix. reduvius. Cases in which one or other of 

 these ticks occasioned much pain and distress are recorded by 

 Hussem, Raspail, and Dr Cosson. Besides these there is a 

 formidable tick well known at Angola (Ix. monbata). Its 

 habits are like those of the common bed-bug. Severe pain 

 comes on two hours after the person is bitten. It likewise 

 attacks animals. The Ix. carapato is similarly troublesome in 

 Brazil. Another very disgusting arachnid liable to attack man 

 is the Galeodes araneoides. This large spider-like creature, two 

 inches in length, commonly attacks camels and has an extremely 

 venomous bite. One or more species of the dung-beetle mites 

 (Gamasidse) have also been known to fasten themselves on 

 man. According to Latreille, they first get attached to the 

 clothes of travellers, whence they pass to his body, and there 

 shift about, producing great torment. Another disagreeable 

 arachnid is the little harvest bug (Lepius autumnalis), which 

 not only excites irritation during its crawling motion on the 

 human skin, but even succeeds in burying itself near the hairs. 

 The irritation thus produced is almost unbearable. This mite 

 attacks various animals, especially dogs and cats. I myself 

 once 'suffered severely from this species in consequence of fond- 

 ling a young wild rabbit which, as I afterwards discovered, was 



