356 
The Ohio Naturalist. 
[Vol. V, No. 8. 
quite reasonable to expect to find them where the archesporium 
is so commonly multicellular. But in Batrachium, or at least in 
the material collected for study, the number of megaspores which 
divide and the number of embr 3 ’o sacs that develop embryos 
seem very few. In many cases only a few of the ovules matured, 
perhaps two or three, as was seen in the ripened carpels and also 
in the material sectioned. 
The functional megaspore passes through the two, four and 
eight celled stages and the nuclei arrange themselves normally 
(Fig. 20-23). The two synergidae stain much darker than the 
egg cell and the antipodals than the polar nuclei. After the 
conjugation of the polar nuclei the resulting definitive nucleus 
was very readily distinguished by its enormous size (Fig. 24). 
While the polar nuclei are ap])roaching each other the antipodals 
enlarge and seem to take on definite walls, and the embryo sac 
begins to widen below. At the time of fertilization the anti- 
podals are situated in an elevated crater-like j^otich (Fig. 24). 
The lengthening of the embryo sac is greater on the distal than 
on the proximal side and extends beyond the chalaza near where 
the antipodal ])ouch is situated. The antipodals are typically 
those of Ranunculaceae resembling almost exactly those of R. 
delphinifolius. The nuclei sometimes divide (Fig. 27) but usually 
only three were present. They persist for a long time staining 
quite deeply and can be distinguished even in quite mature 
ovules (Figs. 31 and 33). 
The entrance of the pollen tube into the embryo sac and the 
actual phenomenon of fertilization was not observed in Batra- 
chium. The pollen tube was traced well down into the stigmatic 
tissue, found emerging in the cavity of the ovulary and again 
seen among the glandular cells of the shorter integument and 
traced into the micropyle. One might expect anything since 
Overton (10) reported parthenogenesis in Thalictrum ])ur- 
])urascens. Coulter (3) found the second sperm cell much disor- 
ganized at the time of its discharge in Ranunculus septentri- 
onalis and Miss Thomas (14) discovered double fertilization 
occurring in Caltha palustris. Double fertilization is also 
reported by Xawaschin (11) for Delphinium elatum and by 
Guignard (7) in Ranunculus flammula, R. cymbalaria. Anemone 
nemorosa, Helleborus foetidus, Nigella sativa and X. damascena. 
In Batrachium, the fact that so few ovules develop and the 
traces of the pollen tube found in those that do, seems to set aside 
entirely the occurrence of parthenogenesis. The peculiar pale 
nucleus shown in Fig. 2b may be the second sperm nucleus. In 
one slide there was what might be taken for double fertilization, 
but the evidence was so unsatisfactory that the writer prefers to 
leave the question unsettled. 
