272 Misses M. Stephenson and M. D. Whetham. 



25 cc. samples of the diluted medium by the extraction method of Hopkins 

 and Fletcher [1907, (2)], and weighed as zinc lactate. 



The disappearance of lactate from the medium and the synthesis of total 

 lipoids is summarised below and shown graphically on Curve 2. 



Day of 

 experiment. 



Lactic acid present ; 

 grm. in 100 e.c. of 

 medium. 



Lactic acid utilised ; 

 grm. in 100 cc. of 

 medium. 



Total lipoids formed ; 

 grm. in 100 cc. of 

 medium. 







0-68 



o-oo 



o-oo 



3 



0-66 



0-02 



Not estimated. 



8 



0-13 



0-55 



0-014 



10 



o-oi 



-67 



016 



12 



0-00 



Total 



-014 



Gi-rm. nitrogen synthesised per 100 cc on 10th day, '018. 



0-6 



0-9 



oz 



Lactic 



acid. 

 qperioocA 

 J rhcdi. 



00)5 



O-OIO • 



O-005 



Toted 

 lipoids 

 gpenoo cc 

 medium 



Day& 



Disappearance of 

 LoxIlc acid. 



Days 



Synthesis of 

 lipoid 



'It will be seen from the above that the organism readily used lactic acid as 

 its sole source of organic food material, and that the course of its growth 

 does not differ materially from that on glucose and acetic acid already 

 established. Similar results were obtained when the lactic acid was added 

 in the form of calcium lactate. The relationship between the total lipoids 



