— 3 
ee 
1907] GOW—SPATHYEMA FOETIDA 135 
ward rapidly, crowding the cells in the base of the nucellus, some 
of which break down. At the same time it undergoes two more 
transverse divisions, forming a row of three megaspores, the inner- 
most of which functions (jig. 4). 
The reduction division and the successive divisions up to the fer- 
tilization stage of the embryo sac proceed as usual (fig. 5-7). In the 
reduction division eight chromosomes were observed, and sixteen were 
counted in the vegetative cells. During the maturing of the embryo 
sac, it lengthens and becomes from one and a half to two times as 
Fic. 5.—First nuclear division of embryo sac. FIG. 6. Rene nuclear division 
of embryo sac. Fic. 7.—A, mature embryo sac; 0, oosphere; n, primary endosperm 
nucleus; a, — cells; B, antipodal cells, and phuleiapeete nucleus with two 
nucleoli. All 
long as it was at the first division of the megaspore nucleus. The 
increase is all toward the chalaza, with very little lateral increase. 
In fact, as the sac elongates it frequently contracts in the middle. 
Of the material examined early in March, very few ovules were 
found in which the division of the archesporial cell had taken place, 
In many of the ovaries examined about April first the embryo sac 
was in the fertilization stage.3 
3I give the earliest date at which the plant develops to the stage of growth 
described. As a matter of fact, many plants are belated, and flower buds may some- 
times be found in re middle of April still unopened; but this is exceptional. 
