ON THE HIGHER CRYPTOGAMOUS PLANTS. 109 



Suminski's statements and opposed others. He stated that he had observed 

 distinctly the production of the young plant (or rather the terminal bud for 

 the new axis), in the interior of the so-called ' ovule,' but believed the sup- 

 posed origin of it from tlie end of the spiral filament to be a delusion. He 

 regards the globular cell at the base of the canal of the ' ovule ' as itself the 

 rudiment of the stem, or embryonal vesicle (the embryo originating from a 

 free cell produced in this), analogous to that produced in the pistillidia of the 

 Mosses. He also describes the development of the ovule differently, saying 

 that the canal and orifice are opened only at a late period by the separation of 

 the contiguous walls of ihe four rows of cells. 



About the same time appeared an elaborate paper on the same subject by 

 Dr. Hermann Schacht*, whose results were almost identical. He found the 

 young terminal bud to be developed in the cavity of one of the so-called 

 ' ovules,' which were developed exactly in the same way as the pistillidia of 

 the Mosses. He stated also that the cavity of the ' ovule ' is not open at 

 first, and he declares against the probability of the entrance of a spiral fila- 

 ment into it, never having observed this, much less a conversion of one into 

 an embryo. 



In the essay of Dr. Mettenius already referred tof, an account of the de- 

 velopment of the so-called ovules is given. His observations did not decide 

 whether the canal of the ' ovule,' whicl! he regards as an intercellular space, 

 exists at first, or only subsequently, 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 contact 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 Suminski, 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 connected 

 together. 



The embryo-sac consists of a globular cell containing a nucleus, and this 

 author believes that the commencement of the development of the embryo 

 consists in the division of this into two, which go on dividing to produce the 

 cellular structure of the first frond. 



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 ray 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 possil)ility of the entrance of 

 the spiral filaments and the impregnation cannot exist until the tearing open 

 of the blind end of the canal in the perfectly-formed ovule, as after the open- 

 ing of the so-called 'canal of the style' in the pistillidia in the Mosses." 



Another contribution has been furnished by Dr. Mercklin J, the original of 



* Linnsea, vol. xxii. 1849. 



t Beitrage zur Botanik, 1. Heidelberg, 1850. Zur Fortpflanzung der Gefass-Cry]3togamen. 



% Beobachtungen aus dem Prothallium der Farrenkriiuter. St. Petersburg, 1850. 



