SEEDS AND SEEDLINGS 29 
19. To learn: Are the cotyledons of the pea and bean of 
any use to the seedling ? 
Sprout several peas and beans on blotting paper, or take some of 
those sprouted in Experiment 1. When the plumules appear, carefully 
cut away the cotyledons and set the plantlets, thus robbed, on mosquito 
netting or paper tied over the surface of a jar or glass of water, the roots 
hanging down in the water. Put with them some seeds similarly 
sprouted, but not mutilated. Let them grow for some weeks and note 
results. 
20. To learn: What ts the relation of the number of cotyle- 
dons to the venation of leaves ? ; 
Observe all the seeds you have been germinating in your experiments 
and arrange them in two lists. In one list include all that have but 
one cotyledon and in the other list place those that have two cotyledons. 
Then examine older plants of the same species and notice which have 
parallel-veined leaves and which have netted-veined leaves. Now 
answer the question, How is the number of cotyledons related to the 
venation of the leaves? 
NOTES ON THE FOREGOING EXPERIMENTS 
1. Bya little experience the student will easily learn how to germinate 
seeds successfully. For the purpose of the first three experiments the 
seeds are not to be planted, but to be kept in full view so that the pupils 
may see exactly what takes place as they sprout. It is well to treat 
them by several of the methods mentioned. 
2. (a) That the seeds swell as a result of absorbing moisture may be 
seen by putting some dry ones side by side with soaked seeds of the 
same kind. Or, fill a small cup with wheat or corn and pour on water 
enough to cover it. The water will all be absorbed and the grain will 
swell and run over. (b) The radicle or caulicle comes out from the seed 
coat before the plumule. 
3. All seeds contain an embryo more or less perfectly developed. 
In many of them, such as the bean, pea, squash, and morning glory, this 
embryo constitutes the entire seed; while in others, such as corn and 
wheat, a good part of the seed consists of food that is stored outside of 
