WSAT IS A SJSHD? 



335 



enclosed in seed- coats, and it is often imbedded 

 in endosperm. 



Suggestions. — Only the most obvious parts and features of 

 seeds have been mentioned here, but these oharaeters are sufficient 

 to enable the pupil to make profitable comparisons between any 

 seeds which may come to his hand. It is good practice to set 

 beginners searching for the cotyledons in large seeds. Where, for 

 example, are the cotyledons in the pecan (Fig. 356), acorn, maize, 



Pig. 356. 



Showing the edible 



cotyledons of 



pecan. 



wheat, castor bean, sweet pea, apple, peach, morning-glory, garden 

 balsam, cucumber, orange, canna, cocoa-nut, and other large seeds ? 

 The parts can generally be made out more easily if the seeds 

 are soaked in tepid water for a few hours. It is more important, 

 however, if facilities are at hand, to set the pupil to the study of 

 the behavior of seeds and plautlets in germination. An interesting 

 series of studies can be made from a comparison of the form of 

 the cotyledons with that of the first true leaves, and of the grada- 

 tion from the character of the first leaves to those which are 

 characteristic of the mature plant. Are there differences in coty- 

 ledons and first leaves between the different horticultural varieties 

 of the same plant, as between the different kinds of tomatoes and 



