32 , ANIMAL PARASITES. 



of the same journal, for the year 1853, Hebra also reports that in 

 one of the most intense cases of the disease, Boeck only met with 

 single living mites. This appears to me to show that the pro- 

 duction of this form of the disease is determined, not alone by the 

 number of the mites, but by a certain disposition of the skin, caused 

 by bad management, or by endemic influences and climate, or com- 

 municated by diseases (local or general), and which consists in the 

 separation of the plastic lymph in large masses. If the manage- 

 ment of the skin in certain districts be particularly bad, and a 

 tendency to plastic cutaneous diseases be also indigenous there 

 (we may refer to the Radesyge in Norway,) the disease may pro- 

 bably become endemic, whilst in other districts it only occurs 

 isolated in particular cases. Fuchs is probably of the same opinion, 

 when he recommends that those individuals who suffer from 

 psoriasis or from squamose cutaneous eruptions, should be infected 

 with itch-mites, a recommendation which is certainly worthy of 

 consideration for the elucidation of this subject. For the views 

 just expressed, notwithstanding the shortness of our acquaintance 

 with the existence of this disease, we already find, in praxi, various 

 vouchers from the most different countries. Thus, in one case, 

 Fuchs saw pustular itch and the ordinary itch-mites and their 

 galleries upon the whole body, whilst on the elbows and knees he 

 found large scaly crusts (epidermic laminse laid over one another, 

 with immense numbers of mites, with their excrements and eggs), 

 which Hebra and Boeck declared to be identical with the crusts 

 common in Norway. In a second case, which had existed for 

 fourteen years, the pustular itch appeared all over the body, 

 but on the upper-arm, the upper part of the body, and 

 especially on the elbows and knees, nay, in the face, there were 

 crusts of the size of four- to eight-groschen pieces. Rigler, of Con- 

 stantinople, saw these crusts all over the body of a Jew boy, with 

 the exception of the upper-arm, the axillae, the hairy scalp, and the 

 back of the chest. Hebra himself saw these crusts developed in 

 the palms of the hands of a syphilitic patient, whilst on the rest 

 of the body all forms of itch occurred. Biichner, of Tubingen, 

 lastly, describes a case which I reproduce here, from No. 4 of the 

 f Deutsche Klinik/ for 1855, as being peculiarly instructive with 

 regard to this form. The skin of the whole trunk, especially on 

 the right side, was of a dark-red colour in spots, covered on the 

 back with ragged epidermis in the act of being thrown off; it was 

 also thickened on most parts of the trunk, uneven, and in places 



