ELEVENTH ANNUAL MEETING. wi 
I have already discussed in a desultory way the microscopic 
marine fauna of certain districts on the Chesapeake Bay, where 
I have been engaged upon the study of the oyster, under the aus- 
pices of the Maryland Commission, but what I have done has 
been simply preliminary and necessarily incomplete. Before 
we are ready to deal withthe material on which the oyster feeds, 
we desire a more perfect acquaintance with the microscopic life 
which grows upon oyster beds and swims about in the adjacent 
waters. From the fact that the lower forms of life in fresh 
water often appear in great abundance one year, while in the 
next, from some unexplained cause, none of the same species 
will be found in the same situation, we may conclude that simi- 
lar seasonal variations occur in the phases of the microscopic 
life of a given oyster bed and its vicinity. 
Such yearly variations in the abundance of microscopic life 
are probably the causes of the variable condition of the oysters 
taken from the same beds during the same season of different 
years. Violent or sudden changes of temperature are probably 
often the cause of the destruction of a great amount of the min- 
_ute life upon which the oyster feeds. Backward and stormy 
seasons doubtless also affect the abundance of the microscopic 
life of the sea. All of these questions have, however, as yet been 
scarcely touched, and, judging from the disposition of many of 
our students of zoology to be content merely with a description 
of new species and the compilation of lists, instead of also en- 
tering into investigations of the life-histories, the relative abun- 
dance of individuals, and the influence of surrounding condi- 
tions upon the forms they study, it will take some time yet be- 
fore we get the information so much desired. When we arrive 
at this knowledge we will know why it is that oysters taken 
from a certain bed are in good condition for a season or two, and 
then for one or more years are found to be watery and of poor 
quality, as well as why it is that the oysters of certain beds, 
which for years have had a high reputation for their fine quali- 
ties, are suddenly found to be more or less green in the beard, 
as I have been informed is now the case with the oysters of 
Lynn Haven Bay, Virginia. 
Speaking of the abundance of the Wavicula ostrearia of Kiitz- 
