320 M. Miiller on the Development of the Lycopodiacese. 



tion, antheridia and oophoridia. The spores of the latter cer- 

 tainly germmate ; of the former, it is still doubtful. 



The antheridium-spores correspond to those of such cryptoga- 

 mia as are formed to the number of four in a mother-cell. 



The oophoridium-spores correspond to the ovule of the higher 

 plants ; nearest to those of the Rhizocarpede if the ovule is under- 

 stood as a mother-cell produced by the axis, inside which the 

 plant is formed. It appears to me that nothing can be objected 

 to this : the inner membrane then would correspond to the em- 

 bryo-sac of the ovule of Rhizocarpece, and the outer in like man- 

 ner would be the analogue of the external membrane of the same 

 ovule. Since in these, according to Mettenius (Beitr. z. Kentniss 

 der Rhizocarpeen), the embryo-sac originates by the deposition 

 of membranous substance, or rather by the secretion of the in- 

 ternal membrane, so also must it be formed in the Lycopodium 

 ovule in the same manner, since it is produced at a later period. 



If this comparison, of the oophoridium-spore with an ovule, 

 have a good foundation — and I see with pleasure that Spring is 

 of the same opinion, which so much the more strengthens me in 

 my views that I did not yet venture to assert them in the second 

 section, and only determined to regard them as clear and correct 

 after subsequent explanations — the Lycopodium ovule thus be- 

 comes of as much consequence in a systematic point of view as 

 that of Rhizocarpece has become since an impregnation has been 

 distinctly pointed out in it. Perhaps I may be allowed to express 

 briefly and conclusively what here presses itself upon us invo- 

 luntarily as a necessary consequence^ in propounding here five 

 chief stages in the formation of plants. Four of them have per- 

 haps already been propounded by many authors ; but hitherto 

 they have never been displayed in connection with one another. 



The vegetable kingdom commences with a single cell. It becomes 

 a mother-cell, new cells being formed in its interior. The daughter- 

 cells propagate the species in a similar manner, these again also 

 becoming mother-cells. This is the case in the Bacillarice and 

 plants of the genus Protococcus. Schleiden will pardon me if I 

 reckon the Bacillarice and Desmidiacea decidedly among plants. 

 In Frustulium I believe that I have distinctly observed a single cell 

 expand itself into the so-called siliceous lorica, inside which new 

 chlorophylle-like cells were formed, from which the species was 

 again propagated in the same manner. This I have clearly ob- 

 served in my Frustulia polymorpha from the North Sea — no mat- 

 ter where this be arranged, since my honoured friend Kiitzing 

 has passed it over in silence in his work on the Bacillarice. I be- 

 lieve that I saw it also in an Achnanthes, which appeared to me 

 to be Ach.panduraformis. Moreover I have observed in Closterium 

 Acus cell-formation in the interior from cytoblasts, which wholly 



