DEKMANYSSUS AVTUM. 63 



Kirby and Spence, and Alt, denominate the disease produced 

 thereby acariasis, and think, as it sometimes occurs in genreral dys- 

 crasic and adynamic tabes, it has to do with those cases of phthi- 

 riasis, in which the parasites lived not only upon, but in the skin. 



To the latter form probably Fuchs' Cnesmus acariasis = 

 Milben-Hautschabe, amongst the pathognomonic signs of which, 

 besides derangements in the urinary system and itching in the 

 skin, is the existence of the parasites in the skin (the so-called 

 Phthiriasis internet) . Fuchs saw mites like lice produced in the 

 tissue of the uninjured skin, and form peculiar bursting tumours. 

 The patient, who was consumptive, complained of itching of the 

 skin and urinary disturbances, and suffered from ectropium senile 

 of both eyes, as well as hypopyon of the left eye. Upon the 

 skin of the neck and back she exhibited numerous, dingy red, 

 very painful boils, on scratching which small mites, like lice, 

 crept forth from them in thousands, together with a clear, putres- 

 cent fluid. We do not know, however, whether these animals 

 came out of the cutis, or the subcutaneous cellular tissue, nor has 

 this species of mite been hitherto exactly determined. According 

 to all experience it cannot be transferred to healthy subjects; 

 just as Bourguignon asserts, for instance, that the mites of 

 animals usually attack only sickly individuals of the animals pre- 

 ferred by them. According to Fuchs, a case of LavaPs and one 

 of Kurtze's may also belong to this form. The patient always 

 died in the last stage of consumption. 



Bory's case must also probably be referred to this place. A 

 little while before the death of a dropsical woman, it was observed 

 that with an improvement, itching also constantly occurred, and 

 this gradually became stronger, and finally insupportable. When- 

 ever the woman scratched herself, thousands of little, brownish 

 animals came forth and crept into the linen ; so that when it was 

 very warm, she was obliged to change her linen from three to six 

 times a day, on account of the immense number of animals which 

 crept forth. 



To the section of Dermanyssus Avium Martiny also refers ErdPs 

 mite in the pimples of the human skin, and regards it as the 

 male of Alt's mite, from which it is only distinguished by a longer 

 proboscis, even projecting beyond the palpi (fig. 11). Whether 

 in ErdFs case we have to do with the true mite of our domestic 

 birds is uncertain. Simon narrates a case in which the mite 

 nestled upon the skin of a woman who was otherwise healthy. 



