100 CLASSIFICATION AND DESCRIPTION OF BACTERIA 
together,’ of the content of many cells which leave their empty cell 
walls behind them. In the first case a readily stainable, in the latter 
case an unstainable ‘symplasm’”’ is produced. Lohnis later states 
that all bacteria multiply not only by fission but by gonidia. These 
may become exospores, grow to full-sized cells, or enter the symplastic 
stage. Some of the gonidia are said to be filterable. Hort (1917) 
working independently in England studied B. typhi and stated that 
simple binary fission was not the only method of reproduction. He 
had previously received similar evidence in a study of typhus fever. 
‘Rosenow (1917) in studying acute anterior poliomyelitis believed that 
he has observed a transmutation. All of these data from so many 
different sources point out the fact that bacteria may pass through 
different stages and that we are not justified in excluding all aberrant 
forms as contaminations. Should these data be further confirmed, 
the bacteriologist may find it necessary to alter his methods of analysis. 
The Descriptive Chart of the Society of American Bacteriologists. 
Bacteriologists, for some time, have been working out a system for 
classifying bacteria. The Descriptive Chart of the Society of American 
Bacteriologists represents a stage in the development of this effort. 
A history of the development of the card and the numerical system 
for recording the characters of bacteria has been prepared by Harding 
(1910), a very brief outline of which will be given here. 
Johnston (1895) first called attention to the possibility of using 
some such method as the Dewey decimal system for recording the 
important characteristics of bacteria. A committee which in its 
report suggested the beginnings of such a procedure was appointed. 
Conn adopted their suggestion and used such a system in his classifi- 
cation of dairy bacteria. <A real attempt to use a group number such 
as our present one was made by Kendall (1903) at the Lawrence Experi- 
ment Station. This is reported by Gage and Phelps (1908). The 
genus classification of bacteria proposed by Migula was used as the 
basis for their report. 
The present chart has a group number depending on the determina- 
tion of ten characteristics. It has been recently described by Rehn 
and Harding (1916). This system of recording the characteristics of 
bacteria has not met with entire approval on the part of many of the 
workers. One of those who was instrumental in introducing this 
numerical system has said that it was a thing to be regretted. Whether 
it is or will be of any value may only be determined after it has been 
used to study certain groups. This, however, has been done by a very 
few bacteriologists. Harding (1910) reports the study of the Ps. 
