BULLETIN 
TORREY BOTANICAL CLUB. 
Vol. XIV.) New York, February, 1887. {No. 2. 
Notes on Diatoms. 
By C. HENRY KaAIN. 
Within the last few years the number of students of the 
Diatomacez has vastly increased. The literature of the subject 
has been greatly enriched, the classification of species is more 
definite, and the valuable aid afforded to geologists by the 
investigation of newly discovered fossil deposits has drawn atten- 
tion to the fact that the study of these forms is not without prac- 
tical results. The researches in regard to the structure of the 
diatom frustule, notably those of Dr. J. H. L. Flogel, Prinz and 
Van Ermengem, and Hon. J. D. Cox, while productive of much 
discussion, are likely to lead to valuable conclusions. Some 
observers are devoting their attention to the study of the life 
history of the Diatomacee, and the number of such students 
should be increased, for there are many points in this connection 
that require verification and further investigation. It is under- 
stood that our veteran diatomist, Prof. H. L. Smith, to whom we 
are indebted for the system of classification now so generally 
adopted, has prepared a work upon this subject, and its publica- 
tion is hoped for at an early day. Very little has been done in 
this country in the way of figuring the species of particular dis- 
tricts, and monographs upon our remarkable fossil deposits 
would be very desirable. 
Most unfortunately, many are only familiar with diatoms as 
they are received in a cleaned state, except, perchance, such as 
may be met with in a casual gathering of pond life. Such per- 
sons would often be pleased to make original collections, but for 
lack of knowledge in regard to where to look for and how to 
gather these little plants. This knowledge is only acquired after 
considerable experience. In the writer’s early experience, most 
