264 Dr. Dickie on the Ovule of Euphrasia officinalis. 
minish the tendency to call in question the observations on the 
Hemp long since recorded. Still, the action of the pollen, what- 
ever be its nature, cannot generally be set aside. 
It will be necessary to allude briefly to the stages through 
which the embryo passes. The first or earliest condition is that 
of a simple cell, the germinal vesicle of Amici and others ; it may 
be compared to the reproductive cells of some of the Algae, and 
might be denominated with propriety the sporoid stage. The 
appendage termed ^ suspensor ^ is worthy of notice ; it is usually 
very highly developed in the sporoid embryo, and more so in 
some plants than in others ; in some of the Crucifercej for example, 
it attains considerable dimensions. I have seen an embi-j'o of 
T>raba verna ^ J ^ of an ineh long, with a suspensor three times 
that length. Mr. Griffith describes the embryo in Gnetum as 
being attached to an enormously long, tortuous, but irregularly 
twisted cellular suspensor, its length varying from 3^ to 5 inches ; 
the whole length of the seed being about 1 inch. 
Different opinions are entertained respecting the true nature 
of this appendage. According to Schleiden^s view it is part of 
the pollen-tube ; in the Orchidece it would seem from Amici^s ob- 
servations to be part of the embryo-sac ; he states that the part 
of the sac which was in contact with the pollen-tube becomes 
elongated upwards, dividing likewise into cells, which are trans- 
parent and situated one above another, so as to form a large 
confervoid filament ; thus traversing in the opposite direction the 
course followed by the pollen-tube, becoming enlarged and pass- 
ing through the orifices of the tegrnen and testa, and being pro- 
longed even as far as the placenta. According to Mohl the 
suspensor is essentially connected with the embryo, both being 
produced by the growth and division of the germinal vesicle, the 
lowest cell, the embryo, growing faster than the others. In 
TropceoluiUj however, the development of the suspensor seems to 
precede that of the embryo ; such at least is the result of ^Ir. 
M^ilson^s observations upon that plant*. It has been already 
stated that the embryo in its first stage may be compared to the 
spore of an Alga ; future observations may aflbrd greater reason 
than at present for saying, that the sporoid embryo of some 
phsenogamous plants germinates in situ, emitting a confervoid 
filament, and requiring no transference to a new nidus, but find- 
ing in the interior of the embryo-sac all the conditions neces- 
sary to its existence and future development as a spore up to a 
certain period. In such Algae as Vaucheria, Derbesia, &c., the 
spores usually escape from the cell in which they are produced; 
being furnished with cilia they are enabled to disperse them- 
selves abroad, after a time they become fixed, and produce a 
• London Joinnal of Botany, vol. ii. p. G23. 
