214 DEVELOPMENT OF THE OVULUM 
E. 4. 5. Pollen seen by two faces. 
2. Pollen ea shortly after. 
8. Ditto sometime after. 
9. Outer membrane of pollen. 
F. During impregnation. 
Pl. 55. G. 1. Long section of ovulum after impregnation ; 
stigma sphacelated. 
2. Vitellus and part of the tercine pushed before it. 
3. Long section of ovulum, somewhat earlier. 
4. Embryo of No. 1. 
5. Base of the vitellus. 
6. Cells towards its apex. 
H. 1. Long partial section of secundine and vitellus, 
shewing the embryo to be external to that sac. 
2. Long section shewing the communication between 
the vitellus and chalaza. 
3. Embryo. 
4. Chalaza. 
5. Vitellus and its process separated. 
K. 1. Long section of ovule considerably advanced ; 
division of the cotyledons is seen as à are i 
face to face. 
2. Cotyledons and embryo separated, the sac of the vi- 
tellus remaining enclosed between the crura of the 
cotyledons. 
Fig. L. 1. Ovule and ovarium at a very early period. 
2. Do. separate; a. nucleus ; 6. secundine ; c. primine. 
3. Apex of the secundine, two pollen tubes have entered. 
4. Do. the hollow conical-shaped process, including one 
tube which appears about to enter the foramen. 
Pl. 56. M. 1. Represents longitudinal section of the ovule, 
part of the ovary and stigmatic canal. The side of the canal, 
from which the papilla arise, as well as that in communication 
with the cap, are of a yellowish colour, and mucilaginous 
appearance. One side of the stigmatic tissue, that next the 
_ ovule, is carried lower down than the opposite one. The ter- 
