[Vor. 7 
296 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
action, however, may have been due to a small amount of bac- 
terial decomposition products. Even in the presence of sodium 
nucleinate, as in culture 17, the amount of growth when the 
cotyledons were excised after 2 days is much less than in the 
control (cotyledons uncut) in solution C, culture 4. The data 
seem to indicate that no proper nutrient substitute for the coty- 
ledons has been found in these organic substances. Some addi- 
tional experiments in which sugar was used in connection with 
nitrogen-containing substances have not served to change ma- 
terially the conclusions which may be drawn. In other experi- 
ments urea and nucleic acid were used, but neither of these 
has been as favorable as sodium nucleinate or glycocoll. It is 
true, however, that sodium nucleinate has increased more than 
any other compound thus far used the growth quantities in the 
cultures lacking cotyledons. 
The importance of the cotyledons in the vigorous development 
of the seedling is an ancient observation. Bonnet (1754) demon- 
strated that beans and buckwheat grew less rapidly when the 
cotyledons were eut off, and more important still, he observed 
the persisting effect of this early difference, stating the matter 
in the following words: ‘‘La meme différence, ou une différence 
analogue, a subsisté entre ces Plantes pendant toute la durée 
de l’accroissement. Il a toujours été facile de distinguer les 
unes des autres." 
Sachs (059) observed the same fact a century later while 
devoting more attention to the physiology of absorption and 
nutrition. Discussing numerous experiments designed to deter- 
mine the interdependence of organs and tissues in the embryo, 
Van Tieghem (73) refers incidentally to the problem here dis- 
cussed. 
While Schmid (94), Hannig (04), and Smith (07) have con- 
tributed many interesting observations regarding the nutrition 
of the embryo and the capacity of different parts to develop or 
regenerate, these facts do not closely relate to the present in- 
vestigation. Dubard and Urbain (113), however, emphasize the 
favorable effects of the endosperm of certain grains in the early 
stages of germination. They directed their work primarily 
toward determining the capacity of the embryos to develop in 
the absence of the endosperm. 
