a 
154 The Botanical Gazette. [May, 
An automatic device for rolling culture tubes of nutrient 
agar. 
GEO. F. ATKINSON. 
(WITH PLATE XI.) 
Rolled culture tubes of nutrient agar agar are so convenient 
for the separation of many micro-organisms, and are employed 
by so many investigators for the study of the growth and con- 
formation of colonies that any device for rolling them success- 
fully is worthy of note. Especially is this the case when such 
device is, under certain circumstances at least, an improve- 
vising some means of rolling the tubes with pr ecision b 
Ing use of the water supply commonly provided for in! 
tory fittings. It is possible with a stream of cold wate 0 
a faucet to so hold with the hands and revolve a tube bl 
distribute and fix the nutrient agar in a thin and tolera : 
even film. But many failures result and at best the tate 
far inferior to one rolled on ice. ing the 
Recently I have made an automatic device for peor 
ubes under a continuous shower of cold water aS perfectly ble 
regularly as it is possible to do on ice and with far wale 
y re ‘ 
€ven though a constant supply of ice is within piel 
1 book of M 
Mead Bolton: chi Handboo 
Sciences, vol, vr, Schizomycetes, etc. Reference Ha 
