THE BEGINNINGS OF LIFE. 281 



Since only a casual allusion has hitherto been made 

 to the mode of origin of Torul<e^ it will be necessary 

 to speak more distinctly concerning this subject, and 

 also with reference to the mode of origin of other 

 forms of Fungus-spores in solutions in which previously 

 no such incipient organisms could be recognized. They 

 appear, as a general rule, to arise somewhat more 

 slowly than Bacteria, and their existence is often sig- 

 nificant of a lower or impaired fermentative energy in 

 the solution in which they occur. 



As to the origin of ordinary Torula cells, their first 

 appearance may be watched in various kinds of 

 solutions, though I have found none more suitable for 

 this purpose than a weak solution of neutral ammonic 

 tartrate in distilled water 1 . During the past summer 

 I found that Bacteria and Torula cells soon appeared in 

 such a solution when placed in a flat-bottomed watch- 

 glass and merely protected by an inverted glass. After 

 twenty-four hours or more (according to the tempera- 

 ture), if the watch-glass be removed, without shaking, 

 to the stage of a microscope, and if the flattened portion 

 of the surface of the glass be scrutinized by a powerful 

 immersion lens 2 , numerous small but quite distinct 

 colonies of Torula cells may be seen scattered over this 

 area, the members of which are perfectly motionless 3 . 



1 About 10 or 15 grains of the crystalline salt to an ounce of water. 



2 I generally employ a ^" objective, and frequently double its 

 ordinary magnifying power by the use of a long draw-tube, so as to get 

 an amplification of about 1000 diameters. 



3 Other Torula cells, however, often exhibit distinct oscillating move- 

 ments. 



