On the Growth of certain Fresh-water and Soil Protista. 163 



Composition. 



Inoculation, 

 March 8. 



Observations on March 13. 



4 c.c. 

 1. 

 2. 

 3. 

 4. 

 5. 



9. 

 10. 

 11 

 12 

 13. 

 14. 

 15. 



Miquel tap + 6 c.c. tap — 

 + 1 c.c. cane sugar solution 



+ solid tyrosin 



+ solid phenylalanine 



+ 1 c.c. cane sugar 



+ solid tyrosin 



+ solid phenylalanine 



+ 1 c.c. cane sugar 



+ solid tyrosin 



+ solid phenylalanine 



+ 1 c.c. cane sugar 



+ solid tyrosin 



+ solid phenylalanine 



+ 1 c.c. cane sugar 



+ solid tyrosin 



+ solid phenylalanine 



1 Controls. Not 



[ inoculated 

 J 



"i r 



[inoculated with J 

 j stale manure j 



J I 

 I Inoculated with I 

 | leaf mould ] 



Inoculated with 

 ploughed soil 



Inoculated with 

 soil under 

 grass land. 



Few bacteria only. 



Sterile. 



Sterile. 



A few soil flagellates. Some ciliates. 

 Very large numbers of soil flagellates 



and of soil amcebse. 

 Large numbers of flagellates ; a few 



ciliates. 

 A few soil flagellates. 

 Very large numbers of flagellates. 

 Large numbers of flagellates. 

 Very few flagellates. 

 No flagellates. 

 Very few flagellates. 

 No flagellates. 

 Very few flagellates. 

 Fair number of flagellates. 



The above Table illustrates the fact that while the minute soil flagellates 

 thrive best in tyrosin or in phenylalanine solutions, yet they are able to 

 develop in solutions containing cane sugar. Cultures were made with the 

 object of ascertaining the effect of various other organic substances on the 

 growth of the flagellates. The flagellates in these cultures were derived for 

 the most part from a stock tube of Euglena culture in tyrosin, in which 

 Prowazekia was also very abundant. The following list embodies the results 

 obtained with various organic substances. Save where otherwise mentioned, 

 the organic compounds were added in the proportion of 1 c.c. of a 1-per-cent. 

 solution to 10 c.c. of the optimal Miquel mixture in tap water. 



Growth of the flagellates. 



Peptone Good growth. 



Tyrosin (OH.C 6 H 5 .CH 2 .CH(NH 2 ).COOH) Very strong growth. 



Tyrosin (added solid) Optimum growth. 



Phenylalanine, C 6 H 5 .CH 2 .CH(NH 2 )COOH (added solid) Strong growth. 

 Alanine CH 3 .CH(NH 2 ).COOH (0-5 c.c. of 1-per-cent. 



solution) Fair growth. 



Glycocoll, CH 2 (NH 2 ).COOH Fair growth. 



Phenylglycocoll, C 6 H 5 .CH(NH 2 ).COOH No growth. 



Allantoin , No growth. 



Saccharin No growth. 



Cane sugar Good growth. 



Tartaric acid No growth. 



These cultures showed that the soil flagellates were able to grow in tubes 

 containing a large variety of organic substances, in many of which Euglena is 



