Growth of Organs in Culture Media. 
133 
II. Lecithan Compounds. 
Koch 1 has lately described the preparation of various com- 
pounds with lecithans, but it is uncertain whether these compounds 
are colloidal mixtures, mechanical mixtures or true chemical com- 
pounds. It seemed of interest to study the behavior of these 
substances in ether solution, when subjected to dialysis in rubber 
bags suspended in ether. 
The preparations used in these experiments were made accord- 
ing to the method described by Koch. For the dialysis tests the 
solutions of the lecithan compounds were evaporated to dryness 
at 38 0 and the residues ground up with ether. The extracts were 
filtered and the filtrates placed inside of rubber bags and dialyzed 
against ether for thirty-seven days. The dialysates were tested 
every week to see if the substance combined with the lecithan 
diffused. 
Compounds of lecithin with glucose, lactic acid, strychnin, 
digitonin, salicin, urea, creatin, creatinin and caffein were pre- 
pared. It was found that the glucose and lactic acid dialyzed 
completely, the strychnin, digitonin and salicin dialyzed par- 
tially, while urea, creatin, creatinin and caffein did not dialyze 
at all. 
82 (607) 
The relative importance of stroma and parenchyma in the 
growth of certain organs in culture media. 
By MOYER S. FLEISHER and LEO LOEB. 
[From the Departments of Pathology of the Barnard Free Skin and 
Cancer Hospital and the City Hospital of St. 
Louis, Mo.] 2 
In experiments carried out about fifteen years ago, one of 
us observed that during the regeneration of skin, the epithelial 
cells are able to penetrate into and to grow in coagula of blood 
and of blood plasma. 3 This suggested to him that it might be 
iKoch, Journ. Pkarm. and Exp. Ther., 1911, ii, p. 239. 
2 We wish to express our thanks to Dr. D. L. Harris, director of the Pathological 
Laboratory at the City Hospital, who put the facilities of his laboratory at our dis- 
posal at a time when our laboratory had not been finished; and also to Dr. M. G. 
Seelig, who very kindly assisted us in a number of our experiments. 
s Archiv f. Entwicklungsmechanik, Bd. VI., 1898; Johns Hopkins Hospital 
Bulletin, January, 1898; American Journal of Anatomy, Vol. III., 1904. 
