Origin and Development of the Vegetable Embryo. 51 
to presume, from his knowledge of the researches of MM. Brown 
and Ad. Brongniart, that there was no essential difference in the 
mode of fertilization in these families, M. Amici goes on to say 
that he considered new researches necessary to the confirmation 
of his conjectures, and this more than ever after the publication 
of the supplemental note of Mr. Brown, in which the mucous 
tubes,^^ instead of being regarded as pollen-tubes, were stated to 
be apparently distinct from them, although engendered or pro- 
duced by their influence. If this last statement were incontest- 
able, not only would Schleiden^s theory be totally overturned, 
but Amici^s idea, that the elongation and penetration of the 
pollen-tube into the coats of the ovule is a general law, w^ould be 
devoid of ground. 
The want of means and leisure had prevented the prosecution 
of his researches on this subject until the publication of Gaspa- 
rini’s observations on Cytinus kypocystis revived M.Amicfls desire 
to determine these points, and he commenced a minute investi- 
gation of the organs of fructification of the Orchidacece. These 
have confirmed him in the earlier opinion of Mr. Brown, and he 
regards the strings of tubes descending into the ovary as really 
bundles of pollen-tubes. He has moreover been able to deter- 
mine the precise state of the ovule before the arrival of the pollen- 
tube ; then, how the latter penetrates the coats and behaves in 
relation to the embryonal vesicle ; and lastly, observed the imme- 
diate changes which follow, in the ovule, the introduction of the 
pollen-tube. All these go to support his former observations, 
and exclude the idea of the conversion of the extremity of the 
pollen-tube into the embryo. 
In the first place is offered the evidence on which he founds 
the opinion that the six bundles or cords of tubes descending into 
the ovary are prolonged pollen-tubes. Regarding the description 
of the appearance and course of these tubes, given by Mr. 
Brown, as altogether agreeing with the characters of pollen- tubes 
in other phanerogamous plants, it only remained to determine 
the identity of the pollen-tubes attached to their granules, and 
entangled in the thickness of the stigma, with the other tubes 
of a supposed different origin, and (hypothetically) produced in 
the immediate vicinity of the former ; this identity was established 
several times by compressing the stigma between two glass plates, 
and observing that the tubes were continuous with each other. 
The slight peculiar characters proposed to be founded on the 
coagulations, &c. in the mucous tubes,^^ Amici considers valueless 
for distinguishing them from pollen-tubes ; these coagulations, 
sometimes interruptions of the continuity of their cavities, being 
consequent on the gradual withering of the layers of the stigma 
and style, which interferes with the communication with the parts 
4* 
