CHAPTlER III. 



Storage of Nourishment in the Seed. 



22. Nourishment in the Embryo. — Squash-seeds are not 

 used for human food, since they have medicinal properties 

 that make them undesirable for that purpose, but beans and 

 peas are important articles of food. Whether the material 

 accumulated in the cotyledons is an aid to the growth of 



the young plant may be learned from 



a simple experiment. 



23. E:xperiin.ent 7.* Are the Coty- 

 ledons of a Pea of any Use to the Seedling ?i 

 — Sprout several peas on blotting-paper. 

 When the plumules appear, carefully cut 

 away the cotyledons from some of the seeds. 

 Place on a perforated cork, as shown in Fig. 7, 

 one or two seedlings from which the cotyle- 

 dons have been cut, and as many which have 

 not been mutilated, and allow the caulicles 

 to extend into the water. Let them grow 

 for some days, or even weeks, and note 

 results. 



24. Experiment 8?- Does the Amount 

 of Material in the Seed have anything to do 

 with the Rate of Growth of the Seedling? — 

 Germinate ten or more clover-seeds, and 



iibout the same number of peas, on moist blotting-paper under a bell jar. 

 After they are well sprouted, transfer both kinds of seeds to fine cotton 

 netting, stretched across wide-mouthed jars nearly full of water. The 

 roots should dip into the water, but the seeds must not do so. Allow the 

 plants to grow until the peas are from 4 to inches high. 



Some of the growth in each case depends on material 



1 The pea is used in a large number of the experiments liere given, because it 

 germinates at a comparatively low temperature, and the young seedlings are very 

 hardy and thrive readily in the schoolroom, 



2 May he a home experiment. 



Fig. 7. — Germinating Peas, 

 growing in Water, one 

 deprived of its Cotyle- 

 dons. 



