WITH PURE COLLOIDAL SILICA 83 



met with mixed with Torulas (Plate 10, Fig. 59), 

 while in others the Bacteria were in smaller num- 

 bers, forming scattered groups as seen in Fig. 56, 

 showing organisms taken from a tube that had 

 been heated to 135 C. 



In each case the fluid in the tube was well shaken 

 before the centrifuge was used, so as to dislodge 

 the organisms from the bottom of the tube, where, 

 with this solution, they seem principally to form, 

 rather than in the light flocculent sediment. 



In repetition of previous cultivation experiments 

 some of the contents of tube No. 186 were in- 

 oculated into an ammonic tartrate solution; and 

 when this was examined, after nine days, though 

 the bulk of the fluid was still quite clear, the flask 

 contained a very distinct amount of sediment, 

 which on examination was seen to be composed 

 of masses of Torulas intermixed with a few large 

 Bacteria (see Plate 10, Fig. 61). A similar ex- 

 periment made with some of the contents of tube 

 No. 193, which had been previously heated to 

 135 C., also showed after nine days a very dis- 

 tinct sediment at the bottom of the flask, though 

 this on examination was found to be principally 

 composed of masses of rather large Bacteria inter- 



