256 
PALEONTOLOGY: C. D. WALCOTT 
brought Old World horse culture to America, we should be puzzled at 
the similarities observed between these traits on the two hemispheres, 
but would probably set it down as another case of assumed independent 
invention. This investigation shows that the invoking of independent 
invention, to be more than a plea of ignorance, must rest upon specific 
data. 
The final discussion of this subject will appear in full in the Anthropo- 
logical Papers of the American Museum of Natural History. 
DISCOVERY OF ALGONKIAN BACTERIA 
By Charles D. Walcott 
SMITHSONIAN INSTITUnON. WASHINGTON 
Presented to the Academy, April 9, 1915 
At a meeting of the Botanical Society of Washington, held April 6, 
1915, I spoke upon the subject of 'Prepaleozoic Algal Deposits' and in 
this connection called attention to the 
existence of bacteria in association with 
the algal deposits of the Newland Hme- 
stone, a formation of the Beltian series 
of Algonkian rocks in central Montana. 
In a preliminary publication^ I stated 
^ that it was quite probable that bac- 
teria were the most important factor in 
*' the deposition of the Algonkian lime- 
\> stones. At that time no definite bacteria 
had been discovered. From the collec- 
tions made during the season of 1914 
many thin sections were prepared. 
These were examined by Dr. Albert 
Mann, plant morphologist of the De- 
partment of Agriculture, assisted by Mr. 
Charles E. Resser of the National Mu- 
seum, with the result that bacteria were discovered in three of the 
sections, which were cut from an algal form included under the generic 
term Gallatinia as defined in the preliminary paper upon the Algonkian 
Algal Flora.2 
The bacteria consist of individual cells and apparent chains of cells 
which correspond in their physical appearance with the cells of Micro- 
Fig. 1. Characteristic gcoups of 
Micrococcus vaccinae. (After Cohn.) 
Very highly magnified. [Encyclopae- 
dia Britannica, 11th Ed., Vo]. Ill, p. 
160, fig. 5-B.] 
