Vol. 36 



BULLETIN 



No 9 



OF THE 



TORREY BOTANICAL CLUB 



SEPTEMBER, 1909 



Stimulation of storage tissues of higher plants by zinc sulphate 



Berenice Silberberg 



^The fact that chemical poisons under certain conditions and in 

 certain quantities are of a stimulating nature to plants has been 

 well established through the work of Raulin, Richards, Ono, Ya- 

 shudi, Latham, Watterson, and others. A complete list of the 

 references on the work done in this field may be found in the 

 papers by M. E. Latham* and A. Watterson. f These investi- 

 gations, however, have been conducted chiefly upon lower plants 

 and the seedlings of higher ones. Little has been done upon the 

 mature forms of the higher plants, or upon their various parts and 

 tissues. This article attempts to describe some investigations on 

 the effect of zinc sulphate stimulation on the storage tissues of 



some of the higher plants. 



The work was done in the botanical laboratory of Barnard 

 College, Columbia University, during the years 1907 and 1908, 

 under the direction of Dr. H. M. Richards, to whom the writer 

 is deeply indebted for his kind interest and assistance. 



The investigation was in two parts, — first, the eflfect of solu- 

 tions of zinc sulphate of various strengths upon the formation of 

 periderm and callus, and second, the effect of such solutions upon 

 the respiration of the tissue. 



All zinc sulohate solutions weaker than normal were made up 



* Latham, M. E. Stimulation of Sterigmatocystis by chloroform. Bull. Torrey 

 Club 3a: 337. 1905. 



t Watterson, A. The effect of chemical irritation on the respiration of fungi. 

 Bull. Torrey Club 31 : 291. 1904. 



[The Bulletin for August, 1909 (36 : 421-488) was issued 3 S 1909 J 



489 



