THE NUTRITIVE VALUE OF THE FOOD RESERVE IN 
COTYLEDONS 
B. M. DUGGAR 
Physiologist to the Missouri Botanical Garden, in Charge of Graduate Laboratory, 
Professor of Plant Physiology in the Henry Shaw School of Botany of 
Washington University 
Considerable work has been done in respect to determining 
the capacity for growth of immature and mature seed-plant 
embryos separated from the endosperm or from the cotyledons. 
Yet this work seems to have been of comparatively little sig- 
nificance in ascertaining whether, under any conditions of ger- 
mination and growth, these natural food reserves may be par- 
tially or completely substituted for in establishing the seedling 
with normal vigor in the soil or in the usual culture solutions. 
Reference will be made later to some of the more important 
literature bearing on the questions to be presented in this paper. 
The data here reported are, however, preliminary and intended 
primarily to give the results of some experiments (1) demon- 
strating, in those cases where the cotyledons serve as a food 
reserve, the striking importance of these seed-leaves in com- 
parison with certain organic substances as a source of food for 
the normal and vigorous establishment of the young plant under 
cultural conditions, and (2) suggesting the possibility that carbo- 
hydrate or hydrocarbon food material stored outside the em- 
bryo, as in the case of corn, may be of far less significance. 
Doubtless the assumption has been quite generally made that 
in the case of peas, beans, and other plants in which the coty- 
ledons furnish practically the entire food reserve these seed- 
leaves may constitute the chief source of organic food until the 
first green leaves are developed. It has seemed to the writer 
that interesting physiological problems might be approached 
through a critical study of the early food reserves, and pre- 
liminary tests with Canada field peas confirmed this assumption. 
Accordingly, the first series of experiments with Canada field 
peas and with field corn were made merely to determine quan- 
titatively the extent to which the excision of the cotyledons, 
or of the food supply stored outside of the embryo and the 
scutellum, influenced normal growth. 
ANN. Mo. Bor. Garp., Vor. 7, 1920 (291) 
