1895. ] Embryology of the Ranunculacee, 301 
In regard to the large cells of the ovule in such species as 
Caltha palustris, Ranunculus septentrionalis and Delphini- 
um tricorne and the comparatively small cells of Aquilegia, it 
seems that we have a phenomenon which may be correlated 
with the habitat of the plant. In the marsh dwelling Caltha 
we find the largest cells, followed in order by Ranunculus 
septentrionalis, R. recurvatus which thrive better in moist 
soil; then come Delphinium, Hepatica and R. abortivus 
which flourish in a drier soil. On the other hand Anemon- 
ella, Thalictrum, and especially Aquilegia, whose cells are 
very small, are particularly dry soil plants. This is not 
given as a theory or explanation, but merely as a suggestion, 
for I do not know how far the facts in different genera and 
species of other families contribute to the support of such a 
view or whether they contradict it. 
Besides the Ranunculacee, unusually large antipodal cells 
have been observed in Delphinium villosum,'* Orntthogalum 
nutans, Gladiolus communis and Crocus. 1 have also ob- 
served large antipodal cells in Feffersonta diphylla. 
As to the large antipodal cells, which with their numerous 
nuclei become so rich in protoplasm, it may be said in har- 
mony with known facts, that they have passed from a for- 
mative into a nutritive condition which we find paralleled in 
the internodal cells of Chara and Nitella.** 
Bloomington, Ind. 
EXPLANATION or PLates XVII-XX. 
Figs. 1-10, Delphinium. 
Figs. 1 and 2. Median longitudinal sections of very young ovule. 
X 335. In fig. 1 two initial cells can be seen; in fig. 2, only one, which 
ced. 
Figs. 4-8. Median longitudinal sections of the nucellus. Fig. 4. 
The nucleus of the large initial cell of the embryo-sac is in the spindle 
Stage of division; at the upper pole are centrospheres. X 335-—!'lg- 5- 
The initial cell has divided transversely, the lower cell being larger. 
**Strasburger, Ueber Befruchtung und Zelltheilung, 38, 41- 1878. 
*Strasburger, Histologische Beitrage, 5:99, 100, etc. 1893. 
