Scientific Proceedings. 



159 



in (254) 



A study of the influence of lecithin on growth. 1 



By A. J. GOLDFARB (by invitation). 



[From the Laboratories of Biological Chemistry (at the College of 

 Physicians and Surgeons) and Zoology , of Columbia University^ 



A reexamination of the evidence upon which was based the 

 stimulating properties attributed to lecithin included experiments 

 on tadpoles and very young kittens. Danilewski believed that 

 lecithin (one part in about 15,000 of water) caused in tadpoles an 

 increase of 300 per cent, in weight, and about 200 per cent, in 

 size, over the control animals. 



My own experiments included three series of over 1,200 tad- 

 poles. In each series the lecithin varied in strength from 1/150 

 per cent, to 2 per cent, (the toxic concentration). In one series 

 (1) the tadpoles were not fed, in another (2) they were given 

 minced worm, in the third (3) they were given a liberal supply of 

 plant debris. 



The tadpoles that zvere kept in lecithin solutions did not show any 

 greater increment in zveight or size than the controls of the same 

 series. There was a marked difference, however, in both the size 

 and weight of tadpoles of one series compared with the tadpoles 

 in the corresponding solution of another series, due to the kind 

 (and presumably the amount) of food given. Individuals of series 

 I were smallest and weighed least ; those of series 3 weighed 

 from 3 to 6 times as much and were twice as broad as the tad- 

 poles in the same strength of solution in series 2. 



Young kittens (over 50 in number) were treated as follows : 

 Series 1. Lecithin was injected subcutaneously daily in doses 

 of from 0.0006 to 0.004 gram. Control animals received subcu- 

 taneously equal volumes of physiological salt solution. The in- 

 crease in weight was somewhat greater in the kittens that received 

 the lecithin. 



Series 2. Lecithin was injected subcutaneously in doses of 

 from 0.0 1 to 0.32 gram daily. The kittens that received the 



1 1 am greatly indebted to Professor Gies and Dr. W. N. Berg for the lecithin 

 made by them for use in these experiments. 



