There is a close resemblance to the embryo sac of Gymnosperms (pines, spruces, etc.). The prothallus is very much reduced, and projects

through the slit in the spore-covering. In the development of the female germ-cell after fertilization, there is an elongation of the upper part (see e, Fig. 14), forming the part called the suspensor, a

body which is not found in other cryptogams, but is present in embryos of flowering plants.

We now pass to phenogamous or flowering plants, in which the