MISCELLANEOUS INFECTIONS 613 
''Judging from reports and based upon the observa- 
tions of Morse upon Grouse disease it would seem that the 
incubation period of the disease is about eight to ten 
days. However, one of the third lot of our birds died 
Avithin three days of its arrival at this Garden, and there- 
fore within three days of its exposure to the second 
arrivals ; if it be correct that this second lot brought the 
disease and the third lot did not have it, it would seem 
that the incubation period can be as short as three days ; 
how long it may be is only suggested by the fact that some 
of the third lot did not die for three weeks after arrival 
and exposure. All the Gambel's and scaled quail suc- 
cumbed to the disease, but two of the twelve bobwhite 
survived. It would seem that although these last birds 
probably introduced the disease, they still possessed more 
resistance than the others, for the second death among 
them occurred seventeen days after the first death. The 
epidemic as we have seen it here seems to be the same 
as Grouse disease of Scotland and as the Grouse disease 
in this country as reported by Morse (Bureau of Animal 
Industry Report 109, May 18, 1907). 
"The means of transmission of the disease is not 
exactly known, but is in all probability by a pollution of 
the food, the water supply or the ground. Since the lesions 
are so marked in the lower ileum, cecum and colon, a 
possible transmission by cohabitation must not be entirely 
overlooked. There does not seem to be any means of 
limiting the epidemic in a flock by segregation or sacrifice 
of the infected birds, because symptoms are few and do 
not appear until shortly before death. Each bird would 
have to be put into a separate cage until proved infected. 
Scrupulous cleansing of the enclosure is desirable, but its 
efficiency is difficult to estimate. ' ' 
