iS 



HOW A PLANT GETS OUT OF THE SEED. 



Figure 



Buckwheat with two cotyledons or 

 ttec-ki \ii ur.feldtd. 



Figure 19. 



10. CASTOR-OIL BEAN. The seed 

 of castor-oil bean is the source 

 from which oil is derived. The 

 seed of our common variety is 

 longer than broad, nearly oval, 

 with a white fleshy outgrowth. At 

 one side is a prominent ridge which 

 divides the seed into two halves. 

 On the lower side the seed is 

 rounded out. The seeds of our com- 

 mon variety are smooth, shining, 

 gray in color marked with brown 

 spots. Fig 19. We will now cut 

 the seed lengthwise; the hard, 

 smooth testa is somewhat brittle. 

 The bulk of the seed is made up cf 

 endosperm which is very oily, and 

 contains an abundance of albu- 

 men. Starch is abssnt. The small 

 embryo occurs in the endosperm. 



Fig. 20. 



Figure 20. 



Castor off bean. The sculptured testa or 

 seed coat. The caruncle shown at car . 



HOW PLANTS GERMINATE. 



Cross-section S3 a 



castor oil bean, f elongat- 

 ed embryo surrounded by 

 the endosperm and the seed 

 coats on the outside, e . 



We shall now undertake to find out some The faruncfe , car an /% u t- 



growth over the hilum com- 



sirnple things about the way plants germinate, inerfrom the micropyie. 

 and this can be done only by experimenting. This is the only 

 way that we can acquire the information we want. For these pur- 

 poses it will be neccessary for the teacher to get a box or pan 

 three or four feet long, two feet wide and four inches deep. 

 Fill this with three inches of sand, moisten and plant with two 

 dozen beans jind two dozen peas. The box should be kept at a 

 comfortable temperature during the day, a room in which child 



