108 REPORT— 1851. 



bers, certain cellular organs of two distinct kinds. The first, which he terms 

 antheridia, are the more numerous, and consist of somewhat globular cells, 

 seated on and arising from single cells of the cellular Marchantia-like frond. 

 The globular cell produces in its interior a number of minute vesicles, in 

 each of which is developed a spiral filament, coiled up in the interior. At 

 a certain epoch the globular cell bursts and discharges the vesicles, and the 

 spiral filaments moving within the vesicles at length make tlieir way out of 

 them and swim about in the water, displaying a spiral or heliacal form, and 

 consisting of a delicate filament with a thickened clavate extremity ; this, the 

 so-called head, being said by Count Suminski to be a hollow vesicle, and to 

 be furnished with six or eight cilia, by means of which the apparently volun- 

 tary movement of the filament is supposed to be effected. 



The second kind of organ, the so-called ' ovules,' are fewer in number and 

 present different characters in different stages. At first they appear as little 

 round cavities in the cellular tissue of the pro-embryo, lying near its centre 

 and opening on the under side. In the bottom of the cavity is seen a little 

 globular cell, the so-called embryo-sac. It is stated by Count Suminski 

 that while the ovule is in this state one or more of tlie spiral filaments make 

 their way into the cavity, coming in contact with the central globular cell. 

 The four cells bounding the mouth of the orifice grow out from the general 

 surface into a blunt cone-like process, formed of four parallel cells arranged 

 in a squarish form and leaving an intercellular canal leading down to the 

 cavity below. These four cells become divided by cross septa, and grow 

 out until the so-called ovule exhibits externally a cylindrical form, composed 

 of four tiers of cells, the uppermost of which gradually converge and close 

 up the orifice of the canal leading down between them- Meanwhile the 

 vesicular head of one of the spiral filaments has penetrated into the globular 

 cellule or embryo-sac, enlarged in size and undergone multiplication, and in 

 the course of time displays itself as the embryo, producing the first frond 

 and the terminal bud whence the regular Fern stem is developed. In con- 

 sidering the import of these phaenomena, the author assumes the analogy 

 here to be with the process of fertilization in flowering plants, as described by 

 Schleiden, regarding the production of the embryo from the vesicular head 

 of the spermatozoa as representing the production of the phanerogamous 

 embryo from the end of the pollen tube after it has penetrated into the 

 embryo-sac. 



The promulgation of these statements naturally attracted great attention, 

 and since they appeared we have received several contributions to the history 

 of these remarkable structures, some confirmatory, to a certain degree, of 

 Suminski's views, others altogether opposed to them. 



In the early part of 1849 Dr. Wigand* published a series of researches 

 on this subject, in which he subjected the assertions of Suminski to a strict 

 practical criticism ; the conclusions he arrived at were altogether opposed to 

 that author's views respecting the supposed formation of the organs, and he 

 never observed the entrance of the spiral filaments into the cavity of the so- 

 called ovule. 



About the same time M. Thuret-j- published an account of some observa- 

 tions on the antheridia of Ferns. In these he merely confirmed and corrected 

 the statements of Nageli respecting the antheridia, and did not notice the 

 so-called ovules. 



Towards the close of the same year, Hofmeister| confirmed part of 



* Botanische Zeitung, vol. vii. 1849. 



t Ann. des So. Nat. Jan. 1849. ser. 3. vol. xi. Botanique. t Botanische Zeitung, 1849. 



