ACARINA OE MITES. 



133 



and cat, producing various forms of "mange." Sarcoptcs (S. 

 mutans) also produce the " scaly leg " of fowls. 



Another form of Scabies is produced by some mites known 

 as Demodicidce. These aoari live in the hair follicles and 

 sebaceous glands, and produce the so-called red mange in dogs 

 (fig. 57). The same species, Demodex folUculo'rum, is found on 

 man and varieties on other animals. In dogs (v. canis) this 

 follicular mange appears as red patches around the eyes, and 

 spreads over the body. It commences as red spots, which 

 gradually become purulent. In the matter from these pustules 

 will be found the mites (fig. 58), and also in the hair follicles. 



Fig. 59.— Beetle Mite (Oribata orbicularis), 



A, Adult ; B, immature form following the six-legged larval stage ; 

 matic organ ; Ai, ungues (claws) of adult ; Ei, ungues of e. 



pseudo-s tig- 



Family Oribatidse or Beetle Mites are so called on account 

 of their hard covering of integument. Many of them are shiny 

 objects which cluster together upon the trunks of trees, especially 

 fruit trees. They have a pair of very curious processes situated 

 on the progaster ; these two bodies are called pseudo-stigmata 

 (c, fig. 59). One of the most abundant forms is Oribata 

 orbicularis (fig. 59), which varies in colour from deep shiny 

 black to brickdust-red. This mite may be found in large 

 clusters on the bark of plum, damson, and other trees, where 

 it feeds off the spores of lichens, fungi, and the ova of other 



