48 PROGRESS OF VETERINARY SCIENCE AND ART. 
the cat without reference to its discoverer. Hering’s memoir 
is an imperishable monument to his industry and talent; 
much may be added from the vastness of the subject, but 
little amended or corrected.* 
The acarus of the pig, classed by Hering, in 1835, amongst 
the doubtful species, has since been discovered by Gurlt, in 
1846, and Hering having seen it after him, says that it 
resembles more the itch-insect of man than any other, f 
The acarus hominis , which has often been the subject of 
spirited discussions and misrepresentations, has recently 
been carefully delineated and described ; first, by Dubini, J 
and next by Bourguignon.§ 
I have lastly to allude to pus acari , which should ever 
carefully be distinguished from the acari scabiei. The sar- 
coptes cynotis || (Hering), sarcoptes hippopodos*\ (Hering), and 
probably the sarcoptes setosus of Dr. Thudichum belong to 
this class. The last-mentioned was discovered by my friend 
Dr. Thudichum, on a man that was supposed to have con- 
tracted scabies from a cow. The patient owned a cow that, 
being mangy, he had been in the habit of dressing with the 
liquid flowing from the dunghill. He soon showed symptoms 
of itch, and imagined he had caught it from the animal. 
Dr. Thudichum, who tells me he also saw the cow, truly 
believes it was an instance of direct contagion. One thing 
is certain, that the sarcoptes setosus is not the true sarcoptes 
bovis , and if any skin affection was excited, it was through 
the transmission of a pus acarus , and not through the 
acarus of scabies. It is fortunate Dr. Thudichum made 
such an admirable drawing; we have introduced it in our 
* In Hering’s memoir, we find that Hofacker thought the acari of the 
cat were most frequently to be seen on the Angora breed, with long coat, 
but it appears, Hofacker did not know the acari ; and Hering has seen 
them in different breeds, and at different ages 
“ It is not known to me,” says Hering, “that the acari of the cat may lire 
on animals of other species ; Hertwig (loc. cit.), informs us of an instance 
in which a horse became affected through a mangy cat. Dr. Berthold saw 
a child of eight years old that had contracted scabies in the same way (see 
Casper’s * Wochenschrift fur die gesammte Heilkunde,’ 1834, Nro. 20.) . 
In one cat, affected with a dry scabby eruption, I found numerous acari 
quite different from those above described. On closer observation they 
showed themselves to be identical with the meal mite. The cat was from 
the house of a baker.” (Hering, loc. cit.) 
t Hering, ‘ Specielle Pathologie und Therapie fur Thierarzte:’ 2d edition, 
1849, p. 200. 
% * Entozoografia Umana,’ del Dottor Angelo Dubini; Milano, 1850. 
The most classical work extant on the subject of parasites infesting man. 
§ ‘ Traite de la Gale de l’Homme,’ par H. Bourguignon ; Paris, 1852. 
|| Cynotis, from kvwv, icwog , canis, and ovg, utoq, auris. 
*f] Hippopodos, from iWo£, equus, 7r Sg, i roddg, pes. 
