[Vol. 2 



822 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 



Schramm ('14) ), containing (NEU^SCU as a source of nitro- 

 gen, the other with nitrogen supplied as peptone and aspar- 

 agin. These media complete were as follows : 



A. 



Agar 10. 00 grams 



( NH 4 ) .>S0 4 .25 grains 



MgS0 4 .*7 H 2 10 grams 



K.>HP0 4 10 grams 



FeS0 4 trace 



Glucose 10 . 00 grams 



Distilled H./0 500 . 00 cc. 



B. 



Agar 10 . 00 grams 



Peptone 4 . 00 grams 



Asparagin 1 . 00 grams 



MgS0 4 .7 H.,0 10 grams 



K 2 HP0 4 10 grams 



FeS0 4 trace 



Glucose 10 . 00 grams 



Distilled H 2 500.00 cc. 



These media, designated "A" and "B," were placed in 

 125 cc. Erlenmeyers, about 25 cc. to each flask, and the flasks 

 placed horizontally until the agar hardened. A relatively 

 large surface was obtained in this way and the harvesting of 

 the alga later was facilitated. In inoculation, the alga was 

 smeared over the surface of the asrar to srive an even arrowth. 



& 



& 



& 



After a growth of thirty days, it was harvested by scraping 

 from the agar surface with a stiff, platinum needle. The cells 

 were then dehydrated with alcohol, acetone and ether, dried, 

 and ground with an equal weight of fine quartz sand. Flasks 

 were set up in duplicate in Wollf wash bottles, using 1 per 

 cent asparagin as a substrate, with an amount representing 



algal powder. Checks were run on 



35 



ams of sand-free 



both the asparagin and the algal powd 



One-half 



sries was taken down at the end of 7 days, the other half at 

 Le end of 15 days, and the NH 3 split off determined by the 

 olin method previously employed. The flasks were kept at 

 temperature of 35 °C. The results are given in table xvi. 



TABLE xvi 



THE ACTION OF DEHYDRATED CHLAMYDOMONAS CELLS UPON ASPARAGIN 



Substrate 

 50 cc. 



Weight 



algal 

 powder 



Nitrogen as NH 3 in 50 cc. substrate 



mgms. 



1 per cent 



7 days 



Net N 



15 days 



Net N 



Asparagin 



.35 grams "A" 

 .35 grams "B" 



.36 

 1.17 



.18 



.16 

 .96 



.45 

 1.84 



.22 



.21 

 1.60 











Water 



.35 grams "A" 

 .35 grams "B" 



.02 

 .03 





.02 

 .04 











The amount of nitrogen in the checks is so small as to be 



.s 



ithin experimental 



NH, snlit off 



