286 Proceedings of the Royal Society of Edinburgh. [Sess. 
Oscillatori a. 
A species of Oscillatorian (not identified) was also experimented with. 
This, when put in a mass in the bottom of a test tube, started to climb the 
wall to the surface. After the migration had taken place so that the 
beginning and end of the mass was fairly clear, the test tube was carefully 
emptied and filled with melted gelatine. When this was set the number of 
filaments per millimetre of length on the test tube was counted under the 
microscope. The numbers in each space of four millimetres were as 
follows : — 
2 , 20 , 42 , 80 , 125 , 190 , 168 , 154 , 164 , 128 , 70 , 28 , 10 , 2 . 
When fitted to a migration curve the correspondence is as illustrated in the 
accompanying diagram (Diagram VIII.). The fit is not good, but the shape 
of the curve suggests that it is made up of two and not one migration 
system. 
