28 CLASS ARACHNIDA 



As the mites are invariably secured by working ainono; 

 raspberries, currants, or other shrubbery which liarbors 

 them, or by walking in grass or low herbage where they 

 occur, sometimes even by sitting or lying for a short time 

 upon grass or clover, it is evident that the best precaution 

 for susceptible persons is to avoid all such exposure. When 

 such a\-oiflance is impracticable, the clothing may l)e made 

 to fit closely at the wrists and ankles, and then as soon as 

 possil>le after having been exposed to the mites make an 

 entire change of clothing, bathe in hot, soapy water, and 

 if any indications of mites are present, wash the affected i)arts 

 with diluted carbolic acid, 1 part to 50 or 100 parts water. 



In the tropics rum or whisky is recommended as a wash, 

 and diluted alcohol can be used with good results. 



\Yith a little pains it is possible to locate the mites, as 

 they may be found before they have completely buried 

 themselves in the skin in the centre of the little red swelling 

 that has been raised by their preliminary irritation, and if 

 they are removed at this stage, instead of being allowefl to 

 bury themselves in the skin the subseciuent inflammation 

 and itching will be largely prevented. 



Family Gamasidae. — The family Gamasidcp contains a 

 large numl)er of small mites, most of them being free or 

 semiparasitic in habit. 



A large number occur as parasites on various species of 

 insects, but the two species to be mentioned here occur on 

 birds, and are sometimes very troublesome. 



The Bird Tick {Dermanyssus avium). — The bird tick is a 

 very familiar form to keepers of cage birds, and is known in 

 many places as the redjnite. It occurs on a great variety 

 of birds, and has sometimes been considered to embrace 

 the chicken tick, mention of which follows, but that is 

 now generally conceded to represent a distinct form. The 

 mites are easily seen with the naked eye and appear as 

 animated red specks running over the bodies of birds, or 

 on the perches, bars of cages, etc. The eggs are laid in 

 cracks or corners of the cage, where may be found also the 

 molted skins and often numerous young and old mites. 



