VARIOUS OTHER PARASITES OF THE SKIN. 593 



and back, mane aod the tail. In eight cows Mobius observed an 

 affection of the same nature, wliich was accompanied by rounded 

 depilated spots. They were treated unsuccessfully for several years, 

 when they disappeared spontaneously after the destruction of sev- 

 eral swallows' nests which were in the stable. Upon two horses 

 which were tormented by dermanyssi, Prietsch observed a large 

 number of superficial wounds which were located mainly upon the 

 neck and back ; the diseased regions were depilated and covered 

 with a furfuraceous matter or thin crusts ; itching was very great 

 in the evening and during the night. In animals of the bovine 

 species these parasites, by becoming accumulated in the ear-passage, 

 produce at times an internal otitis (Gassner); they may penetrate 

 into the middle ear and occasion cerebral accidents. In oxen which 

 were killed as being hydrophobic, Stadler and Schuemacher found a 

 considerable quantity of dermanyssi in the external and middle 

 ear. (See Cutaneous Affections of Poultry). 



As to treatment, we must remove chicken coops from stables and 

 barns, destroy the sw^allows' nests these may contain, and use insec- 

 ticides (cresol, carbolic acid, etc.). The stables must also be disin- 

 fected. 



5. Autumnal lepta (Leptus auiumnalis). This is found in 

 dry grass, ripe grain, upon elder and willow trees. It affects the 

 dog at times (Friedberger), and produces a pustulous eruption in 

 the neighborhood of the muzzle, eyelids, ears, and inner surfaces of 

 the anterior and posterior members, on the belly, genital organs, 

 etc. At the beginning we observe upon the skin small red pim- 

 ples (pimples or pustules) from the size of a poppy to a hemp-seed, 

 on which the leptus is fixed. They may easily be recognized by 

 their scarlet color.^ 



On pressing these pimples a bloody liquid oozes from them. 

 Later they become larger and may reach the size of a ten-cent silver 

 piece, and may also become confluent ; from their surface the hair 

 falls out, .partially or completely. The skin is red and sensitive ; 

 generally we find a moderate pruritus. The eruption may last for 

 weeks, but it disappears by using preparations (ointments, glycerole) 

 with a base of carbolic acid or cresol. 



1 According to Mégnin this seems like the hexapod larvae of the silky Trombidion. 



— N. D. T. 



38 



