CONTRIBUTIONS TO BOTANY. 
209 
in anatropal seeds — not as expressing any action of gradual in- 
version of the nucleus and its tunics, as has been assumed. 
I will now proceed to show that the development of the raphe 
is always normally ventral, or next the placenta, and that when 
it assumes a dorsal position, this is due exclusively to a resupi- 
nation of the entire ovule. I have already explained the differ- 
ence in the incipient development of an anatropal and an atropal 
ovule — that in the former the pullulation of the nucleus is never 
from the extreme point, but always more or less removed from 
it, and in general completely on one side of the placentary 
sheath ; this is either on the upper or the lower face, but some- 
times lateral, and in these cases the growth of the ovule is either 
downwards or upwards, or laterally in regard to the axis of the 
ovary, producing thus either pendent, ascending, or laterally 
horizontal ovules. When the first appearance of the nucleus is 
on the superior side of the funicular sheath, we have a pendulous 
ovule, mth the raphe necessarily on the ventral side of the pri- 
mine (as shown in the marginal figures in p. 204), in all cases 
where the point of its attachment upon the axis of g 
the carpel is at any sufficient distance above the 
base of the cell to allow of its downward growth ; 
but if this point of origin be contiguous to the 
base, then the downward extension of the primine, 
pressing against the bottom of the cell, causes the 
ovule to incline upwards gradually into an erect 
position (turning thus upon its funicle, as Mr. 
Brown first sagaciously demonstrated in the case of 
Euonymus), so that the ovule becomes completely 
reversed, with the raphe upon its dorsal face. In 
the same way, when the pullulation of the nucleus 
is upon the lower side of the funicular sheath, 
we have necessarily an ascending ovule with a 
ventral raphe, produced by the upward expansion of 
the sheath, as in the marginal figures, showing 
the first and two later stages of this growth, which 
prevails in all cases where the ovule has sufficient 
room to expand itself ; but where this production of the funi- 
cular support is close to the summit of the cell, then the pres- 
sui’e of growth causes the ovule to be forced round gradually 
upon its funicle till it becomes pendent, with its raphe in a 
dorsal position. In both these instances of resupination of the 
ovule, there is no removal of the mouths of the tunics from 
their close contiguity to the tela conductrices , — a very import- 
ant feature in the history of its development. These two con- 
ditions of growth of the placentary sheath may be expressed by 
the terms epipyla and hypupyla , — the former from itrl super, 
VOL. I. 2 E 
