PUANBROGAMIA. 219 



Thus we see that the development which takes place here 

 inside of the ovule (which corresponds to the spore-case) is 

 similar to that which in the Lyoopods takes place only after 

 the large spore has separated itself from the parent-plant. 



465. Fertilization takes place as follows: The scales of 

 the cone open slightly, permitting the pollen, which has 

 been carried in the wind, to roll down to their bases where 

 the ovules are. Here the pollen-cells germinate, and their 

 tubes enter the opening in the ovule-ooat and push through 

 the tissues to the archegones, where the pollen-protoplasm 

 is fused with that of the germ-cell (Fig. 123). 



466. As a result of the fertilization, there is first a 

 growth of a row of cells (called the suspensor, erroneously), 

 upon the end of which the embryo begins to form. The 

 root-end of the embryo is always in contact with the sus- 

 pensor, so that, taking the whole embryo at maturity, the 

 suspensor is at one end and the little leaves at the other. 

 Moreover, the root-end of the embryo is always directed 

 towards the opening in the ovule- or seed-coats. The em- 

 bryo proper is composed of a little stem ending in a short 

 root below and bearing a number of little leaves (cotyle- 

 dons) above. The stem ends in a bud, above and within 

 the whorl of leaves. During the growth of the embryo 

 the ovule enlarges, and its coat becomes thicker and harder, 

 and at last, when growth within has ceased, it separates from 

 the parent-plant as a seed (Fig. 124, I). 



467. In germinating, the seed first absorbs water and 

 swells so as to burst its thick coat, the root elongates and 

 pushes out into the soil (Fig. 124, A), soon sending out 

 little branches. The leaves (cotyledons) are in contact with 

 the endosperm, which is rich, in starchy and sugary mat- 

 ters, which afford the plantlet f ood for its growth. Finally, 



