266 Dr. Dickie on the Ovule of Euplirasia officinalis. 
Graminece. Its independence of the pollen need scarcely be 
spoken of in Coelehogyne and Citrus already alluded to. The ob- 
servations of Mohl on the Orchidece lead to the same conclusion ; 
those of Muller on the same family have a similar import. Mr. 
Henfrey in his report already quoted observes, “ The whole 
question appears to be narrowed to the determination of the 
point, whether the germinal vesicle does actually exist before im- 
pregnation, since if that can be proved, all appearances yet ob- 
served may be reconciled by allowing for very slight errors in 
interpreting and delineating them.^^ 
The most careful and trustworthy observers speak with caution 
respecting the real nature of the action produced by the pollen- 
tube upon the ovule in impregnation. We have seen that at 
least one stage of embryo-life is independent of the contact of the 
pollen-tube with the embryo-sac ; this I have ventured to deno- 
minate the sporoid stage. In some few cases, viz. Ccelebogijne and 
others, all the stages are equally so; generally however the 
future progress of the embryo is determined by the action of the 
pollen, whatever the nature of that action may be. The pro- 
duction of true radicle, cotyledons and plumule will constitute 
the last stage of embryo-development, and it is in reference to it 
that the best instruments cease to afford us any precise informa- 
tion. A¥e can trace the progress of the organs in question, but 
we cannot state precisely in w^hat way the action of the pollen 
influences their development. We do not derive any very clear 
information from such statements as those of Oken*, when he 
tells us that the pollen electrifies, animates or inspirits the 
ovarium — that the male imparts nothing in impregnation but 
the solar ray or fluid nervous mass in its semen, which awakes, 
animates and inspirits the quiescent female — that the pollen is 
a most highly differenced electrical product ; the seed-granule a 
wholly indifferent and tranquil mucous mass. The pollen falls 
upon the stigma of the pistil, and irradiation has taken place ; 
the material fruit- capsule gains thereby so much polarity, that 
saps enough ascend, in order to develope the germless seed- 
vesicles.^^ 
The theory of Schleiden had the advantage over all others that 
it directly accounted for the presence of the embryo. Some ob- 
servations of ]\Ir. Griffith seemed to lead to a conclusion nearly 
similar, the difference being that the embryo is not developed 
directly from the end of the ])ollen-tube, but from cells produced 
by that part. It is presumed that no one has hitherto traced a 
tube through its whole length, connected with the pollen-grain 
at one end and with the embryo at the other. 
* Oken’s Philosophy of Nature, Ray Society, 1847. 
