SEEDS. 5 



It should be noticed that while the micropyle constitutes the 

 organic apex of the ovule, the chalaza indicates that of the seed. 



In order to examine the mode of germination or growth 

 in seeds belonging to each of the two great classes of flowering 

 plants (monocotyledons and dicotyledons), obtain a common 

 garden pea, as representing the dicotyledons. A reference to 

 diagrams A and D will indicate the principal parts mentioned. 



Fig. D. 



Fig. A. — A, a pea, enlarged. I, the testa, torn to show 2, the teg- 

 men. 1 3, the micropyle or foramen. 4, the hilum. 



Fig. D. — D, a pea, split in halves. A, the plumule, o, radicle or 

 radicula. CC, cotyledons or seed-leaves. 



Fig. E. 



E represents a legume or pea-pod, split 

 I is the dorsal or back suture (seam or 

 joint) or rib running along the back of the pea. 

 X^EEE^V 2 is the placenta or part to which the pea is 

 attached by the funiculus or cord, 3. 4 is the ventral or belly 

 suture or cord-like junction of the lower part of the pod. The dorsal and 

 ventral suture bind together the two halves — termed valves — of the pod. 



Having thus acquired a knowledge of the organs of 

 growth, let a practical experiment be tried by soaking a pea 



1 Sometimes called Endopleura. 



