1898] SOCIETY FOR PLANT MORPHOLOGY AND PHYSIOLOGY 113 
oping embryo, was held to be well established in case of some 
races of maize by the work of Dudley, Savi, de Vilmorin, Hilde- 
brand, Kérnicke, Sturtevant, Burrill, Kellerman and Swingle, 
McCluer, Tracy, Hays, and others, and in case of some races of 
peas, by the work of Wiegmann, Gartner, Berkeley, Laxton, and 
Darwin. The converse phenomena of the mother plant influenc- 
ing the characters of the developing embryo are occasionally 
reported, for instance in hybrids of Digitalis by Gartner, and in 
hybrids of Nymphzea by Caspary. 
These phenomena are inexplicable by most of the current 
theories of heredity and perhaps in consequence have been neg- 
lected. They necessitated the assumption that hereditary influ- 
ences can be transported from cell to cell for some distance. 
The suggestion was made that this transport may occur either 
along the intercellular filaments which pass through the walls, 
or by means of diffusible substances capable of acting on the 
hereditary particles of distant cells. Townsend’s proof of the 
conduction of the stimulus which results in wall formation, over 
long slender threads of protoplasm in plasmolyzed cells, may be 
considered as hinting at the possibility of the former explana- 
tion, while Beyerinck’s claim, that the developing larvae of some 
gall insects secrete substances which diffuse into and control the 
redone of neighboring meristematic or partially developed 
RSF of the host plant; furnishes some ground for the 
T hypothesis. 
1. The variable effects of hydrocyanic acid gas on plants and 
Plants y - ALBERT F. Woops, Department of Agriculture. — 
sabe cia ‘able families and in different stages of growth were 
found to be aie ne of hydrocyanic acid gas, and were 
kind of i ‘ected by it in different degrees, according to the 
opment. Ana age, and other conditions of growth and devel- 
Within the i eanly tasects, were also found to vary, even 
resistant of me family, in like manner. Mites were the most 
several h any of the organisms studied, often recovering after 
ours of complete paralysis and apparent death. 
