THE CROW AND ITS RELATION TO MAN. 73 
and sight was temporarily restored, but within half an hour the membrane 
reformed and the patient would flutter about like a bird with the cerebellum 
destroyed or with the eyes shot out. 
That death ensued from the acute disease and not merely from starvation 
due to blindness was abundantly proved by caring for sick birds and forcing 
food down their throats, for they died in nearly every instance. While it is 
true that those birds which survived the disease were, in every instance, birds 
that had been blinded in only one eye, we believe that this merely indicates 
that the roup was less severe in those cases, which was the cause at the same 
time of the slight affection of the eyes and of the bird's recovery. 
In 1901 R. J. Weith, of Elkhart, Ind., reported that he was con- 
fident that 10,000 crows died within a radius of 2 miles of that place, 
due, probably, to an epizootic of " roup." 1 
The late Prof. F. E. L. Beal related having seen birds at the roost 
near Langdon, D. C., affected by this disease in the winter of 1901. 
Several hundred birds, partially or totally blind, were noticed aim- 
lessly pecking at branches and running their bills along them in a 
fruitless endeavor to find food. These birds were too seriously 
affected to accompany their companions on their daily search for 
food. 
The writer has witnessed mild outbreaks of this disease at the 
Langdon (D. C.) roost during the four winters from 1911-12 to 
1911-15. In each year a few score of birds were found dead. All 
the sick birds which were kept in captivity and forcibly fed died 
within three or four days. During the winter of 1913-14 the dis- 
ease was prevalent among crows throughout adjacent parts of Mary- 
land and Virginia. 
In the reduction of the number of crows by natural agencies no 
other single factor appears to be so potent as this disease. Birds 
that do not succumb are often so enfeebled that their capture by 
predatory animals is comparatively easy. 
PROTECTION OF CROPS. 
The ravages of crows upon fields of grain and other crops have 
been matters of record almost from the beginning of agricultural 
activities. Before the advent of firearms and the use of poisons 
and deterrents of various kinds the protection of crops was in- 
trusted entirely to " grain minders," whose constant presence in the 
fields during all hours of daylight was necessary. When the early 
colonists attempted to cultivate limited areas of corn and other grain 
along the Atlantic slope, they found themselves confronted with 
many of the same problems that had occupied their attention in 
Europe. The American crows became as troublesome as the rooks, 
hooded crows, and jackdaws had been in their former homes. Some 
1 Country Gentleman, LXVI, 2520, pp. 412-413, 1901. 
