132 MR. HENFREY ON THE DEVELOPMENT 



The archegonia are stated by him to be found exclusively upon the thickened part of 

 the prothallmm (in opposition to Wigand), as I have described them. He further says 

 that the earlier stages of development are difficult to make out, but he believes the 

 papilla originates by the subdivision of one of the cells of the prothallium into four by 

 vertical septa crossing each other, these growing out into a conical body ; the canal, and 

 the cavity at the base (the embryo-sac) are supposed to originate as intercellular cavities, 

 by the separation of the cells bordering them. The canal is closed at first and open after- 

 wards. It is evident from these statements that the earlier conditions of the embryo-sac 

 were overlooked. The mucilaginous filaments in the canal of the archegonium were seen 

 and figured by Schacht, who correctly asserts that they are not decaying spermatozoids, 

 as supposed by Suminski. He states that the embryo originates in the cavity at the base 

 of the archegonium (the embryo-sac) ; but he seems to suppose it to be merely a vegetative 

 growth, as is evident from the concluding paragraph of his memoir : — 



" Since the ' germ-organ ' (archegonium) is not open originally, but closed, the fact of 

 its opening subsequently, when it has become surrounded by a high cellular wall, together 

 with the circumstance that the direction of the orifice is downwards, render it scarcely 

 conceivable how ' spiral-filaments ' could make their way into it ; moreover, in spite of 

 the utmost patience and care, I could never observe a ' spiral-filament ' inside the ' germ- 

 organ,' still less the conversion of one of them into the ' germ ' (embryo). Consequently 

 the impregnation of the Perns, as described by Count Leszczyc- Suminski, is more than 

 improbable, and thus the inclusion of the Perns among the Phanerogamia is by no means 

 justified." 



In these conclusions we see that the bias given by the adherence to Schleiden's doctrine 

 of the origin of the embryo in the Phanerogamia, of which Schacht is one of the leading 

 defenders, has prevented his entertaining the idea of the spermatozoids exerting simply a 

 fertilizing influence. All his argument is against the conversion of one of them into an 

 embryo, so that the hypothesis I have adopted is not touched by the above statement, and 

 it is unnecessary to add further remarks. 



In the following year M. Mettenius* published some important researches on this and 

 allied points in the reproduction of the Cryptogamia, in which, however, he confined him- 

 self, in regard to the Ferns, to a description of the development of the archegonia. In 

 this his statements agree in the essential particulars with those I have given above, since 

 he also believes Suminski to have overlooked the superficial cell covering the embryo-sac, 

 and giving origin by its division to the papilla which subsequently grows up. There is 

 only one anatomical point in which I think he was probably in error, namely, in reference 

 to the mode of development of the papilla, the projecting portion of the archegonium. He 

 states that the first cell is divided into four by crossing vertical walls, that these four cells 

 grow up equably and become divided by horizontal septa so as to form four parallel columns 

 each composed of four or five cells one above the other, between the contiguous internal 

 angles of which the canal leading down to the embryo-sac is formed as an intercellular 

 passage. My observations, as already stated, lead me to believe that the process is some- 

 what different from this, and that Hofmeister's description is more correct. 



* Beitriige zur Botanik, Heft i. Heidelberg, 1850. 



