298 BOTANICAL GAZETTE [May 
himself to discuss the subject of fertilization in which multinu- 
cleate gametes are concerned, endéavoring to present a point of 
view that seems to him fruitful of future results. This portion 
of the paper is headed Theoretical Considerations. 
The material of A. candida came from the vicinity of Colum- 
bus, Ohio, and had been fixed by three methods, in chrom- 
acetic acid, by the weak formula of Flemming, and in saturated 
solution of corrosive sublimate. That fixed in chrom-acetic acid 
proved very much the best for the present study, which desired 
the protoplasmic contents of the cells as free as possible from 
all inclusions such as oils and fats. It is interesting to know 
that the osmic acid of Flemming’s fluid so preserved the oil-like 
material in the protoplasm as to render it insoluble in ordinary 
clearing agents, and very troublesome in all preparations, 
because the globules stained deeply and masked the protoplas- 
micelements. The material killed in corrosive sublimate did not 
present well-preserved nuclei or mitotic figures. The sections, cut 
5 thick, were stained with safranin, gentian-violet, and orange G. 
The preparations confirmed in all essentials Wager’s account 
of the development of the oogonium and antheridium. 
A most interesting stage in this process is the differentiation 
of the so-called “receptive spot,” a region of densely staining 
protoplasm in the oogonium at the point where the antheridium 
becomes applied to the structure. It is certainly true that @ 
papilla from the oogonium is the active agent which works its 
way through the cellulose walls and establishes communication 
with the antheridium. In A/bugo b/iti the papilla actually pushes 
into the antheridium, becoming a swollen process in the interior 
of that structure. The papilla is much less pronounced in 
A. candida, but behaves in a strictly analogous fashion. 
The antheridial tube begins its development and growth 
the oogonium before there is the slighest trace of the oosphere, 
and it may have penetrated to one fifth the diameter of the 
structure before that cell is differentiated. 
The development of the oosphere is an exceedingly interest- 
ing and complex process. Its commencement is indicated by 4 
into 
