200 
CONTRIBUTIONS TO BOTANY. 
bag, and constituting the foramen of tbe primine (micropyle or 
exostome), which from first to last never changes its position or 
its aspect — a most important point to be observed. During this 
action of centrifugal growth, the chalaza, or place of attachment 
of the nucleus, necessarily recedes from its original position, 
remaining at the bottom of the growing bag or primine, the 
extension of the nourishing vessels keeping pace with its down- 
ward growth, and still terminating in the now basal chalaza ; at 
the same time, the enclosed nucleus and secundine severally 
grow upwards, both constantly attached to the budding or cha- 
lazal point of their origin : all this is seen in fig. 5, which repre- 
sents a perfect ovule ready to receive the pollinic influence. We 
find in fig. 6 exactly the same disposition of the parts after the 
ovule has been impregnated, and when the embryo-sac with the 
nascent emhryo has been developed. In these several stages 
we perceive that the foramen of the primine, the mouth of the 
secundine, and the apex of the nucleus, from first to last, all 
culminate towards one common point, while the basal portions 
of the same parts as constantly point downwards : if the expres- 
sion may be allowed, they all retain the same uniform polarity ; 
there is no inversion in any of the parts, or even an approach to 
it ; the hilar or funicular point of attachment is not transported 
from the base of the ovule to its superior extremity, as asserted ; 
and there is no agglutination {soudure) of the primine to the cord 
of the raphe, elongated by this assumed act of semirevolution 
of the ovule. In fine, although the mode of growth, as shown 
in the drawings, is perfectly correct, there is throughout the 
whole description a misconception, and a complete mistake in 
the use of all the terms employed by Mirbel, especially in those 
I have denoted by itahcs. The same mode of growth is again 
still more fully demonstrated in plate 7, in the instance of Tu- 
lipa. Nowhere among the other numerous exemplifications in 
this celebrated memoir can we find any material variation in the 
direction of the parts of an anatropal ovule : this only exists in 
campylotropal or amphitropal ovules, where, of course, owing to 
the curvature of the several parts, from an excessive one-sided 
gi’owth, a more or less partial inversion takes place. 
The same erroneous description is given by the able St.-Hilaire 
in his ‘Morphologie Vegetale’ (p. 540), where he thus defines 
the development of an anatropal ovule. Its first appearance 
upon the placenta is a small protuberance (wrongly said to be 
the nucleus of the future ovule), which by degrees becomes co- 
vered by two cups that rise successively from its base and form 
the future tunics, primine and secundine. The so-called “ ovules 
anatropes, par la courhure graduelle de la base de leur axe, se 
rapprochent peu a peu du cordon ombilical, et apres avoir decrit 
