SEED-LEAVES OR COTYLEDONS 131 



wither, and fall away, and your plant will be in the condition 

 of the right-hand picture on the plate. 



This rise and fall of the cotyledons is characteristic of 

 many seedling plants, for these cotyledons are the store- 

 houses of food materials by means of which the tiny seedling 

 is enabled to get a start in the world, and when they have 

 served this purpose, and the plant is able to shift for itself, 



Tomato Seedlings — The Rise and Fall of the Cotyledons. 



they drop away. The seed-leaves are green, like true leaves 

 with most plants, and they serve the purposes of true leaves 

 until these have been developed. 



If you will sow some seeds of squash or pumpkins you can 

 see the same story told in an even more striking fashion. 

 You doubtless are familiar with the large, deep-green seed- 

 leaves of young squash plants, so smooth and shiny and so 

 different in form and structure from the ordinary leaves of 

 the squash. Or you can get the story told in a somewhat 

 different fashion if you will plant some beans in a paper 

 flower-pot and watch the seedlings as they develop. The 

 cotyledons do not appear to be such definite leaves as are 



