272 BOTANICAL GAZETTE [ APRIL 
suggest that a stage like fig. g represents the two pronuclei 
within the egg, or that fertilization has already taken place and 
the two nuclei are the first two nuclei of the sporophyte. While 
the series shown in figs. 7, 8, and g affords an answer to such 
suggestions, it may be added that vestiges of the pollen tube 
can almost always be detected above the neck of the arche- 
gonium until the oospore nucleus has divided two or three times. 
No evidences of fertilization were visible in these cases, and, | 
besides, the upper nucleus is far too large for a male pronucleus 
just escaped from a pollen tube. If fertilization has not taket 
place, the second supposition is already excluded; but it may 
be added that the nuclei are too large for the first nuclei of the 
sporophyte, they lack the very characteristic appearance of the 
latter, and, further, their position is against any such interpre 
tation. 
The origin of the ventral cell has led several writers to regard c 
it as the homologue of the egg. That this homology is correct, 
the series just described furnishes practically complete proof as 
far as origin and function can furnish it, the only thing lacking 
being an actual case of fertilization. 
THE DEVELOPMENT OF THE OOSPHERE NUCLEUS. 
The development of the nucleus of the cones ee 
decidedly from the usual course of development ascribed — i 
nucleus of the angiosperm oosphere. After the cutting ad 
the ventral canal cell, the nucleus of the oosphere im ing 
enormously in size, as will be readily observed by pag 
jigs. 2.:and 17.3 During this increase in size, there ee 
in the nucleus a series of changes which for some nas A 
difficult to interpret. In fig. 2 the nucleus of the oosp pa u 
not differ much in size or in any other perceptible “— 
the nuclei in the sheath about the oosphere. 
ftes 
ee : i s and 0 
nucleus is in a typical spirem stage. The numerou d in similat 
ios “ 
Coarse radiations about the nucleus were not observ 
and the outl 
: id 15, 
* All the figures are drawn to the same scale except 14 and 15 
sketches, 9, 19a, 24a, 25a, 26a, and 27a. 
