A. Henfrey on the Higher Cryptogamous Plants. 387 
vations did not decide whether the canal of the ‘ovule,’ which he 
regards as an intercellular space, exists at first, or only subse- 
quently, when it is entirely closed above. Some important points 
occur in reference to the contents of the canal. 
The contents of the canal in a mature condition consist of a 
continuous mass of homogeneous, tough substance, in which fine 
granules, and here and there large corpuscles, are imbedded. It 
reaches down to the globular cell or ‘embryo-sac,’ and is in con- 
tact with this. This mass either fills the canal or diminishes in 
diameter from the blind end of the canal down to the ‘embryo- 
sac ;’ in other cases it possesses the form represented by Sumin- 
ski, having a clavate enlargement at the blind end of the canal, 
and passing into a twisted filament below. In this latter shape 
it may frequently be pressed out of isolated ‘ovules’ under the 
Microscope, and then a thin transparent membrane-like layer was 
several times observed on its surface. In other cases the contents 
consisted of nucleated vesicles, which emerged separately or con- 
nected together. 
The embryo-sac consists of a globular cell containing a nucleus, 
and this author believes that the commencement of the develop- 
ment of the embryo consists in the division of this into two, 
prich go on dividing to produce the cellular structure of the first 
ond. 
With regard to the contents of the canal the author says,— 
_ “Although I can give no information on many points, as in 
regard to the origin of the contents of the canal of the ‘ovule,’ 
yet my observations on the development of the ‘ovule’ do not 
allow me to consider them, with Suminski, as spiral filaments in 
course of solution; just as little have I been able to convince 
myself of the existence of the process of impregnation described 
by that author. It rather appears to me that the possibility of the 
entrance ofthe spiral filaments and the impregnation cannot exist 
until the tearing open of the blind end of the canal in the per- 
fectly-formed ovule, as after the opening of the so-called ‘canal 
of the style’ in the pistillidia in the mosses.” 
Another contribution has been furnished by Dr. Mereklin,* the 
Original of which I have not seen, but depend on analyses of it 
published in the ‘Botanische Aeitung,’} and the ‘Flora’ for 1851,f 
and further in a letter from Dr. Mercklin to M. Schacht,¢ which 
appeared in the ‘ Linnea’ at the close of last year. 
He differs in a few subordinate particulars from M. Schacht in 
teference to the development and structure of the prothaltium or 
Pro-embryo, and of the antheridia and spiral filaments; but these 
do not require especial mention, except in reference to the vesicu- 
BO rae a ae 
* Beobachtungen aus dem Prothallium der Farrenkriuter. St. Petersburg, 1850, 
cscs me Zeitung, vol. xxxiii, 1850. + Flora, vol. xxxiii, p. 696, 1850. 
Linnea, vol. xxiii, p. 723, 1850. 
