322 M. Miiller on the Development of the Lycopodiaceae. 



Lastly, we see in the fifth place, that the acts of impregnation 

 and germination have become two independent stages ; then the em- 

 bryo is produced by impregnation inside the ovule , in fact in the 

 embryo-sac, and is at once so fully perfected, that the act of germi- 

 nation is nothing more than an evolution of an already fully -formed 

 part. Here therefore the plant is produced and perfected in the 

 interior of the ovule. 



The degree of importance the Jbycopodiaceae possess in this 

 series is at once evident. They unite the sexual plants with the 

 asexual [Agamce), the plant being actually formed in the interior 

 of the ovule without the occurrence of impregnation. They pos- 

 sess therefore the ovule of the sexual plants and the gemmation 

 of the asexual, and thus make good their place for ever between 

 Ferns and BJiizocarpem. 



2. In the formation of the plant in the interior of the ovule all 

 cells originate singly. This is not in opposition to the law laid 

 down by Schleiden, that the cells are developed within cells. 

 Here the ovule is to be regarded as the common mother-cell for 

 many cells. As we here see therefore distinctly that the cells are 

 formed without impregnation, I must mention a phsenomenon 

 which Spring relates in his " Monographic de la Famille des Ly- 

 copodiacees ^^ in the ^ Memoires de PAcademie Royale de Brux- 

 elles,^ tom. xv. He says that R, Brown has often seen the escape 

 of a fovilla-like mass from the spores of Psilotum triquetrum, and 

 that he also has often noticed it. This may easily be, since we 

 have above become acquainted with a finely granular matter con- 

 tained in these spores. I have never seen any fovilla-like mass 

 escape, but certainly the above-described granular contents, which 

 often become elongated and branched. This phsenomenon how- 

 ever Spring holds to be very important, without giving any further 

 explanation of it. But if in this importance an intimation is given 

 of anything analogous to an act of impregnation, it disappears 

 of itself before the direct proof that the ovules never open to 

 absorb a fovilla. 



Every cell is self -formed, the protoplasma of the ovule being pre- 

 cipitated round a central nucleus, and the outer layer becoming 

 hardened. As in the Rhizocarpecs, where Mettenius [loc. cit.) 

 traced the course of formation of the cell, the cells here appear 

 at first as cavities in the protoplasma, since the substance around 

 the nucleus is so transparent that it cannot be detected. An 

 outer ring of protoplasma alone, more granular than the rest, is 

 to be seen, and the outermost layer of this becomes membrane. 

 I have never perceived a cytoblast here in L/yc. denticulatum ; this 

 structure therefore must be regarded as a modification of cell- 

 formation. 



3. The terminal bud alone is formed by the plant inside the ovule. 



