Origin and Development of the Vegetable Embryo. 59 
consider the pollen-grainy not as the ovule of the plant, but as its 
fertilizing organ; that Schleiden^ s theory of vegetable impregnation 
is false. 
He considers these observations as a complete proof of this 
proposition^ since he worked with such care and perseverance 
that he ventures to consider them incontestable. They refer to a 
single species alone, and this of a family possessing many pecu- 
liarities, but he believes that every one will agree with him in 
idea that the process of fecundation is essentially the same in all 
Phanerogamous plants, that is, in reference to the question whe- 
ther the pollen-grain or the ovule produces the embryo — what- 
ever modifications of the minor points may occur in different 
families. At the end of his memoir the author offers some spe- 
culations which have arisen out of the foregoing observations. 
He asks whether the three germinal vesicles which are formed in 
the upper end of the embryo-sac may not be identical in their 
nature with R. Brownes corpuscula in the Conifer (2 : the chief 
difference between them appears to be, that in the Orchidacece 
the suspensor (the filamentous elongation) consists of a single 
row of cells and takes a backward course, breaking through the 
nucleus and growing out into the seed, the embryo remaining in its 
place ; while in the Coniferce the suspensor is composed of several 
rows of cells and breaks through the embryonal vesicle below, so 
that the growing embryo at its lower extremity attains its fuller 
development outside the embryonal vesicle*. 
K. Muller f has followed the development of ovules in a num- 
ber of plants ; he gives a minute account of his observations on 
Orchis Morio, Monotropa Hypopitys, Begonia cucullata and Ela- 
tine alsinoides. He fully confirms the statements of Amici and 
Mohl with regard to 0. Morio, the only point of difference being 
that he could never see the end of the pollen-tube filled with 
green matter as above described. Otherwise he traced the pollen- 
tube through the foramina of the coats and saw it lying on the 
side of the summit of the embryo-sac. His researches in 0. la- 
tifolia, paludosa, maculata, militaris, Platanthera bifolia and 
Ophrys ovata yielded similar results. In all these the embryo 
was produced from the lower cell of the series produced from the 
germinal vesicle. In Monotropa the pollen-tube is applied di- 
rectly to the apex of the embryo-sac, and the embryo is here 
* It appears to me that this parallel is not well-grounded : have not the 
corpuscula of the Conifercs rather the import of embryo-sacs, like those 
of Viscum, than of germinal vesicles ? This is the opinion of Schleiden. — 
Rep. 
t Beitrage zur Entwickelungsgeschichte des Pflanzen-embryo, von Karl 
Miiller. — Botauische Zeitung, Oct, 15, 22 and 29, 1847. 
