6 
The Ohio Naturalist. 
[Vol. IV, No. 1 , 
ovulary. The tip of the nucellus emerges slightly between the 
injtegiuneiits, the inner of which extends entireh’ around the 
ovule, while the short outer integument does not go beyond the 
middle of the ovule. Just at the base of the stylar canal the outer 
integument, rising freely from the inner one, bends itself abruptly 
upward as if to form a stopper to the cavity of the ovulary which 
at this place is quite large. Guignard (7) says that this upward 
bending accounts for the shortness of the the outer integument, 
and also states that the inner integument became thicker where 
it was not covered by the outer; but the writer saw but little dif- 
ference in the thickness and if any, the reverse was true. Imme- 
diately after fertilization development of the nucellus is very rapid 
( Fig. 6) so that at that stage of the ovule the embr3'0-sac occu- 
pies onlj- a ver>' small portion of the entire body. Endosperm 
also begins to develop, spreading upward and backward from the 
3’oung embryo. When the nucellus has about completed its 
development the endosperm takes on a rapid growth, destroying 
the large mass of nucellar tissue. Simultaneous with this growth, 
the embryo also develops with rapiditj', evidently being well 
nourished by the large endosperm cells (Fig. 8). This growth 
continues until the endosperm entirely replaces the nucellar 
ti.ssue, leaving onl>" a vestige of the latter surrounding it ( Figs. 
9-1 1 ). 
The 3'oung embr\’o, protected by the scutellum, lies on the 
ventral side of the grain, somewhat above the base of the endro- 
sperm and outside of it, except for a ver}- thin layer one or two 
cells in thickness. It is shielded on the outside by the remaining 
nucellar tissue and the carpel wall (Figs. 9-10). 
In Figure ii is shown a nearl}- mature grain cut in longitudinal 
section transverse to the ear. The remains of the nucellus is ver\- 
thin or entirely absent. A little above the base of the grain is 
the young embr3’0, showing the plumule and the .scutellum, 
below which the large suspensor extends with its end surrounded 
with elongated endosperm cells. Across the upper end of the 
grain is shown a strip of endosperm with larger and quite irregu- 
lar cells. There are sixty or more cells across the entire width, 
the cells being comparatively minute in comparison to the .size of 
the grain and not large as is usually figured in the text-books. 
BIBLIOGRAPHY. 
1. B.\TKS0N, W. ]Mendel’.s Principles of Heredit\-. Pp. 40-103. 1902. 
2. CoRRKNS, C. Untersculumgen ueber ilie Xenieii bei Zea mays. Ber. 
d. deut. Bot. Gesellsch. 17 :4io-4i7. 1899. 
3. Dk \'riks, Hugo. Sur la Fecoiidation h3bride de Palbiimen. Comples 
rendiis Acad, des Sc. 4 Dec. 1899 
4. . Sur la Fecoiidation liybride de Fendospenn dans le 
Mai's. Revue gen. de Bot. 15 .\pril 1900. 
5. Focke, W. O. Die Pflanzeu Mischlinge. j). 511. iSSi. 
