SPERMATOPHYTES : ANGIOSPERMS 
367 
simple, being developed entirely within the spores which 
produce them. 
The male gametophyte is represented by a few cells which 
appear within the pollen grain, two of which are male cells. 
When pollination 
occurs, and the pollen 
has been transferred 
from the pollen-sacs to 
the stigma, it is de- 
tained by the minute 
papillae of the stig- 
matic surface, which 
also excretes a sweet- 
ish sticky fluid. This 
fluid is a nutrient so- 
lution for the micro- 
spores, which begin to 
put out their tubes. A 
pollen-tube penetrates 
through the stigmatic 
surface, enters among 
the tissues of the style, 
which is sometimes 
very long, slowly or 
rapidly traverses the 
length of the style sup- 
plied with food by its 
Cells but not penetrat- FlG - 327 - Diagram of a longitudinal section through 
. , a carpel, to illustrate fertilization with all parts 
ing them, enters the 
in p i ace : ,, gt igma ; ff , style ; o, ovary ; ai, ii, 
outer and inner integuments ; n, base of nucel- 
lus ; /, funiculus ; b, antipodal cells ; c, endo- 
8perm nucleug . k egg and one 8yner gi d ; Pt po i- 
len-tnbe, having grown from stigma and passed 
" micr pyle (m) to the egg - After 
Cavity Of the OVary, 
, -i -, . -, 
passes through the 
micropyle Of an OVUle, 
penetrates the tissues 
of the nucellus (if any), 
and finally reaches and pierces the wall of the embryo-sac, 
within which is the egg awaiting fertilization (Fig. 327). 
