1878 Journal of Applied Microscopy 



so on, each j-/^/;-culture bearing the number of the mother culture from which it 

 was taken, with one figure more placed one space more to the right of the decimal 

 point. If but one sub-culture is made, this added figure is always one. If more 

 than one sub-culture is made, the first of these sister cultures is designated (as 

 above) by the number of the mother culture with one in the next right decimal 

 place, the second by two in the same place of decimals, etc., i. e., 401.11,401.12,. 

 401.13, etc. 



This may be better illustrated by a diagram : 



401.1 



401.12 



401.111 401.112 401.113 401.121 401.122 401.123 401.124 401.125- 



_J I I I I I I 



1 1 f 401.1211 401.1221 101.1231 401.1241 401.1251 



401.1111 



401.1132 



401.1121 401.1122 



It will be seen from the above that a single daughter culture is always 

 expressed by the number of the mother culture with the figure 1 placed in the 

 next right place of decimals, and that further cultures made from the same given 

 mother culture are expressed by increasing this last new figure in arithmetical 

 order. This is the key to the system. 



If at any time more than nine sister cultures be made from any one culture, 

 the figures above nine are enclosed in brackets to avoid confusion, e. g., 404.18, 

 404.19, 404.1(10), 404.1(11), etc. 



In cases where the numbers have become somewhat unwieldy, they may often 

 be abbreviated by using exponents, e. g., 401. inil21118=:401. 1^21^3. 



When an unidentified organism is isolated^ it is given the specific number in 

 hundreds which designates the species which it most resembles, but with the 

 tens and units figures running above 50 ; thus, a glanders-like organism would 

 be numbered 451, etc., pending its further examination. If found to be glanders, 

 it would be renumbered below 450, taking the number next above that of the 

 glanders culture last isolated. 



Unidentified organisms, having no striking resemblance to any species 

 possessed by the laboratory, are classed by themselves under one species number 

 (e. g., 10,000) until identified. 



A card system, used in connection with the above system of numbering, 

 offers a complete and at the same time handy record. 



The following card forms'* are given merely as an illustration of the way in 

 which the card catalogue system may be adapted to meet laboratory needs. 

 They are not offered as a complete system, perfect in detail. 



^ The cards have been partially filled out the better to show their uses. 



