CHAPTER II. 



HOW SOnE PLANTS BEGIN LIFE. 



The first aim of this chapter is to develop some fundamental facts 

 in the physiology of higher plants. There are also several minor 

 reasons for taking up work with seedlings in the autumn. There is 

 more time for it, since there is less out of door plant life clamoring for 

 attention ; the temperature is favorable, and children can be prepared 

 to enjoy the native seedlings that the rains bring. The seeds do best 

 planted in sand in wooden boxes. The sand should be kept moist 

 but not wet. 



An idea to be emphasized from the first is that the seed is a little 

 plant with its equipment of food for beginning life by itself. The 

 castor bean seems to me to illustrate this idea more forcibly than any 

 of the other common seeds. The ideas of seed protection and seed 

 distribution are made only incidental here ; they should be impressed 

 throughout the year, but the early summer affords the most striking 

 illustrations. The poisonous quality of the castor bean is well estab- 

 lished by medical records. The seeds are sometimes fatal to man, 

 and I have not been able to find that any animals eat them. The 

 violent expulsion of the seeds is likely to occur on sunny days follow- 

 ing a dense fog or a rain. Mature seed vessels, moistened and then 

 kept is a sunny place in the school room, are pretty sure to throw 

 some of their seeds, but even out of doors many of the seeds are dis- 

 missed gently and fall near the parent plant. 



The structure of the seed is most easily taught by beginning with 

 germinating seeds and then comparing them with unsprouted ones. 

 It is best to keep the seeds in water about twenty- four hours before 

 dissecting them, and the hard seed coat should be cracked with a 

 hammer. The castor bean has also a distinct inner seed coat, but 

 this is hardly worth noticing, particularly as it is not present in all 

 the other seeds. An ovule before fertilization has an opening to the 

 embryo sac through which the pollen grains enter. This orifice is 

 called the micropyle, and through it the radicle forces its way even 



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