8 
W. L. WILLIAMS. 
ORIGINAL ARTICLES. 
THE AIR SAC MITE OF THE FOWL. 
Cytodites Ntidus . Ger, Cytoleichus Sarcoptoides . Meg. 
By W. L, Williams, Prof, of Surgery, New York State Veterinary 
College. 
Although the air sac mite has been studied by numerous 
European'investigators at various dates since Gerlach’s first de¬ 
scription in 1858, we have found no record of the occurrence of 
the parasite or a disease referable to it in any English-speaking 
country, and, indeed, find but a brief mention of either parasite 
or disease, consisting of a mere outline, by Neumann (Non- 
microbic Parasites of Domestic Animals. Translated by G. 
Fleming.) 
During my official connection with the Montana Agricultural 
Experiment Station at Bozeman, Mont., from 1893 to 1896, the 
disease was extremely prevalent, and favorable opportunity was 
offered for clinical observations, which have been augmented 
more recently by importing and cultivating the disease at this 
college. 
The malady first attracted my attention by invading some 
pure bred fowls imported from the Atlantic States to Montana 
by the Experiment Station for breeding purposes. These were 
apparently healthy at the time of their arrival, and remained so 
for three or four weeks. Their permanent quarters not being 
ready they were placed temporarily in yards where occasional 
losses of poultry had previously occurred without attracting 
special attention. By the time the permanent quarters were 
ready a serious and fatal diarrhoea had broken out among the 
turkeys, followed in a few days by a similar outbreak among the 
chickens, and, continuing to spread slowly during the summer, 
caused a loss of over 30 per cent, of the adult birds and about 
50 per cent, of the chicks. 
The chief symptoms of the disease were profuse diarrhoea, ex¬ 
treme debility, and either cyanosis or paleness of the comb. The 
