1898] THE LIFE HISTORY OF EUPHORBIA COROLLATA 421 
A mass of active, glandular hairs develops on the placenta 
above the funiculus. Some of these apply themselves to the 
" inner face of the nucellar neck, which bends toward them as it 
continues to lengthen ( figs. rz, 26, 52). By the time the embryo 
Sac is in the eight-celled stage, the tip of the neck has reached 
the narrow apex of the loculus and is closely appressed to the 
placental tissue (fig. 52). The integuments envelop it, and the 
“outer one becomes attached to the placental tissue in sucha 
_ tanner as to enclose the neck completely. An axial row of 
tells, larger and of looser structure than the surrounding tissue, 
_ Sdeveloped through the entire length of the neck (figs. 26, 
52). These connect with a line of glandular cells that leads 
through the placental tissue to the stigmatic surface of the style 
4 (eg. 52). The pollen tube thus has a definite and direct pas- 
Sage to the modified cells in the neck, which break down as it 
approaches, 
The extremely long synergids hang from the upper end of 
the sac with the oosphere suspended between their free tips 
(figs. 27-29) in the direct path of the pollen tube which passes 
_ between them (fig. 30). The fusion of the polar nuclei takes 
Place Near the egg in either the Icngitudinal or the tranverse 
— *Is of the sac (jigs. 27, 28). The antipodals are very ephem- 
: having been seen but once in several hundred slides. The 
perm nucleus does not divide before the egg is fertilized 
WS: 30 end. m.). Immediately after the entrance of the pollen 
be, the neck of the nucellus and the glandular hairs disappear, 
he outer integument closes the mouth of the micropyle with 
~s© Cap that develops from its inneredge. At the time of fer- 
"ation, when the embryo sac has encroached on the nucellus 
Me base of the ovule, the tissue in this region divides into a 
MSs of small but comparatively thick-walled cells, forming a 
_“Tupon which the sac rests (fig. 11). 
MICROSPORANGIUM. 
When the stamen is but a small swelling (fig. 3 5") there 
Fin four distinct regions, approximately equidistant from 
