2494 



Journal of Applied Microscopy 



high and keeping it raised so long that there was danger of contamination. 

 Apparently, however, there was no instrument on the market more suitable for 

 doing the work. It was evident that something of the same general style as a 

 section lifter was wanted, but with a blade and handle of a material to stand 

 repeated sterilizing in flame ; the blade must be firm, remain smooth after con- 

 siderable use, and must be of the right curve and dip to slip smoothly under a 

 colony, or, when inverted, to cut around it, without requiring the cover of the 

 culture dish to be raised higher than the width of the handle ; and it must be 

 broad enough to pick up a large colony. After experimenting with models ham- 

 mered from brass wire, a model was submitted to the Bausch &: Lomb Optical 



•fo 





^ 



Fig. 2 — n. Wooden frame, in which test tubes are set. />. Test tube, with side tube. <r. Circular 

 connection of rubber tubing, connected with side tubes by T-tubes. </. Richard's filter- 

 pump. 



Co., by whom the instruments similar to those shown in Fig. 1 were made. 

 As completed these are of either steel or of copper, with the blade in two widths, 

 one nine millimeters wide, the other four millimeters ; length of blade, sixteen 

 millimeters; length of handles, one hundred and thirty millimeters; making 

 total length one hundred and forty-six millimeters. The narrow form is used less 

 often than the wide, but is very necessary for certain work. It has proved more 

 practicable to have the two separate instruments than to put two blades at oppo- 

 site ends of the same handle ; since the blades have almost a cutting edge. The 

 instruments have now stood the test of over a year's almost daily use, and are still 

 smooth and serviceable. 



Aa Apparatus for Growing Seedlings and Small Plants Under Sterile Conditions. — 

 In studying the phenomena of " damping off," it became necessary to devise 



