GENETICS: M. B. STARK 
573 
Experiments have been made on the adsorption of organic acids from 
aqueous solution, and the results finally obtained, together with those 
on soaps, all of which have a high positive adsorption, will be reported 
in the complete papers which will be published in the Journal of the 
American Chemical Society. A recent paper by Hardy"^ gives valuable 
information on the application of the principles of surface action to the 
problem of lubrication. Hardy was the first worker to investigate the 
appHcation of the Dupre equation to interfaces between water and 
organic Uquids. Our complete papers will consider the relation between 
adhesion and lubrication. Experiments are now in progress on the heat 
of adsorption of Hquids on solids, both on dispersiod and plane surfaces, 
and calculations are in progress which will relate the results given in 
this paper to the atomic and molecular distances. 
^ Dupre, Theorie Mecanique de la Chaleiir, Paris, 1869, p. 69; Lord Rayleigh, Phil. Mag. 
(5) 30, (1890), (461), Hardy, Proc. Roy. Soc, London, (A) 88, 1913, (303-33), Harkins, 
Brown, and Davies, /. Amer. Chem. Soc, 39, 1917, (354-64). 
2Antonow, /. Chem. Phys., 5, 1907, (384). 
3 F. Schmidt, Leipzig, Ann. Physik, 39, 1912, (1108). 
4 Hardy, Phil. Mag., May, 1919. 
A BENIGN TUMOR THAT IS HEREDITARY IN DROSOPHILA 
By Mary B. Stark 
Zoological Laboratory, Indiana University 
Communicated by T. H. Morgan, October 16, 1919 
1. A non-lethal hereditary tumor. — In a strain of flies with a lethal 
tumor, i.e. a tumor occurring in one-half of the males and causing 
their death (/. Cane. Res., July, 1918; /. Exper. ZooL, February, 
1919) another tumor has appeared as a mutation. The new tumor 
differs from the lethal one in that it is not sex-linked, i.e., it appears 
in females as well as males, and further in that it does not cause the 
death of the flies in which it occurs. 
After several generations of inbreeding of males and females with 
tumors, a stock was obtained which breeds true to the tumor — the 
tumor appearing in all the flies. 
Since the new tumor is not sex-linked its gene is not located in the 
X chromosome. To locate the gene in one of the other chromosomes, 
females with tumors were mated to star dichaete males. The gene for 
