1901] MICROSCOPICAL JOURNAL. 85 
DratToms.—Maurice Peragallo of Clermont near Paris, 
is issuing a “General Catalogue of Diatoms,” printed 
by a sort of hectograph process in 16-page installments. | 
Price 25 cents each. Up to March Ist, 30 installments 
had appeared and included the genera from A to K in- 
clusive. It is in the French language. 
BuBONIC PLAGUE.—The plague is now present in this 
country, in California. Had the State Board of Health 
of California had five thousand dollars at the beginning 
of the outbreak, probably it might then have stamped the 
fearful disease out of California ; but the means and pub- 
lic support were not provided, and the disease has con- 
tinued ; now the legislature has appropriated one hundred 
thousand dollars with which the State Board of Health is 
to try to restrict the plague. 
BROWNIAN MovEMENT.—In his article upon ‘The Be- 
ginnings of Things,’ Dr. Edwards has given us a new 
philosophy of this movement. We call attention thereto 
so that no one will overlook it. Heshows, likewise, that 
there is no such thing as dead matter. 
BIOLOGICAL NOTES. 
THE MULTIPLICATION oF BACTERIA. —A single bacter- 
ium has been calculated by Th. Nageli to weigh one ten 
thousand millionth of a milligram. The length of a gen- 
eration is from fifteen to forty minutes. Supposing all the 
conditions for multiplication to be favorable the results 
are appalling. Cohn has estimated that a single germ can 
produce, by simple fission, two of its kind in an hour; in 
the second hour these would have multiplied to four ; and 
in three days they would form a mass of four thousand 
seven hundred and seventy-two billions,an enormous mass, 
whose weight would amount to seventy-five hundred 
tons. Fortunately, these ideal conditions never exist, 
each germ requires food, and as the supply is always lim- 
ited (not to speak of other items), great numbers starve. 
