SCIENTIFIC PROCEEDINGS 



One hundred fifteenth meeting. 



Abstracts of Communications. 



University and Bellevue Hospital Medical College, April 20, IQ21. 

 President Wallace in the chair. 



105 (1687) 



Tissue weight and water content in a tetracotyledonous mutant 

 of Phaseolus vulgaris. 



By J. ARTHUR HARRIS. 



[From the Station for Experimental Evolution, 

 Cold Spring Harbor, L. I.] 



In 1 91 5 studies of the tissues of normal and variant bean seed- 

 lings were begun in an effort to explain the differential mortality 

 with respect to morphological characters demonstrated in an 

 earlier experiment. 1 



In a first paper 2 it was demonstrated that teratological seedlings 

 show a lower capacity for the development of primordial leaf 

 tissue than do normal individuals of the same strain grown under 

 conditions as nearly as possible identical. In these first experi- 

 ments the conclusions were based upon the green weight of pri- 

 mordial leaves. 



In a second study, tissue weight determinations were based 

 on the trifoliate leaves of the third node as well as on the pri- 

 mordial leaves of the second node. 3 In these two investigations 

 we attempted to determine to what extent morphologically aber- 

 rant seedlings differ from the normal seedlings of the race to which 

 they belong in their physiological characters in so far as these can 

 be measured by the capacity for the production of tissue. The 

 results indicated that teratological seedlings show a lower capacity 



1 Harris, J. Arthur, Science, 1912, N. S., xxxvi, 713-715. 

 * Harris, J. Arthur, Genetics, 1916, i, 185-196. 



3 Harris, J. Arthur, Brooklyn Botanic Garden Memoirs, 1918, i, 167-174. 



207 



