1B REPORT OF THE COMMISSIONER OF FISHERIES. 
exposed to the air by its flow as a creek of many falls and cascades, 
and this corrects it completely. 
Water supply at White Sulphur Springs station.—A visit was made 
to White Sulphur Springs station in January and February to investi- 
gate the mortality among trout fry there. It was shown that the sta- 
tion water varied from time to time in its supply of dissolved oxygen, 
and was for a part of the time markedly deficient in oxygen. There 
was possibly at the same time a deficiency in the nitrogen dissolved, 
but the necessary apparatus to determine this was not available at that 
time. An aerating and de-aerating apparatus ona small scale was put 
in practice by lowering one trough to the floor and passing its supply 
through a perforated box, the water falling a few feet in slender 
streams. This arrangement caused a marked reduction in the losses, 
but did not entirely prevent them. The presumption is that a more 
complete process of the same sort would correct the water entirely. 
Mortality at Allentown, Pa.—In October and November study was 
made of a mortality among brook-trout fry at the Allentown hatchery 
of the Pennsylvania Board of Fish Commissioners. The disease 
proved to be an anemia which was finally ascribed to long continued 
housing of the fry in large numbers in hatchery troughs. The prog- 
ress of the disease in the affected brood could not be arrested, but 
terminated naturally, leaving a considerable percentage of fry in 
apparently good condition. 
Contamination of oysters at Great South Bay, Long Island.—Repre- 
sentations having reached the Department of State through certain 
officials in London that oysters received from New York were con- 
taminated with sewage and presumably with typhoid germs, the matter 
was taken up by the Bureau, and in February an examination was made 
of certain oyster beds at Great South Bay, from which the contam- 
inated oysters were alleged to have come. 
Oysters freshly taken from the beds named, and similar oysters held 
for two or three days in floats on the bay shore were examined bacterio- 
logically and were wholly free from sewage contamination. At 
Patchogue, oyster beds were found exposed to sewage, and though 
oysters taken from them were also free from sewage at this time, 
some danger must have existed, especially at other seasons. The prac- 
tice of floating oysters close to shore, even when not at the mouths of 
creeks or rivers, was found to be more or less a menace to the health 
of oyster consumers. 
The oysters alleged to have been impure were taken in November 
and December, while the investigation was made in February follow- 
ing. Though the beds were then found free of contamination, the 
method of floating the oysters near shore might easily result in their 
contamination during the warmer months of the season, and it is 
