M. Miiller on the Develojjment of the Lycopodiacesc. 247 



The whole of the contents of the mother-cell being now appro- 

 priated in the formation of the secondary cells and the membrane 

 of the latter quite complete, without their form being as yet ne- 

 cessarily perfected, the mother-cells expand in an extraordinary 

 degree, and the secondary cells become more widely separated 

 (fig. 12). It is worthy of remark here that the secondary cells 

 are usually quite free, rarely (as in fig. 12) occurring on the wall 

 of the mother-cell. There are no signs of their being retained in 

 their position by filaments or similar means of attachment ; we 

 must therefore attribute all to the contents of the mother-cell, 

 and assume that the same is of sufiicient specific gravity and 

 thickness to maintain this position. I say we must assume it, 

 since in reality it is not to be observed, for no contents can be 

 made evident in the mother-cells even when the strongest tinc- 

 ture of iodine is applied. This is also always the case with the 

 membrane of the mother-cell : this may equally be treated with 

 the most concentrated tincture of iodine, and it remains transpa- 

 rent and so clear, that, as I have already remarked, it is only to 

 be traced by the closest attention. When one of these mother- 

 cells is beheld for the first time beneath the microscope, the ap- 

 pearance has something very striking about it, since the four cells 

 are always seen in one and the same position without the mother- 

 cell being at all perceived. This definite position of the secon- 

 dary cells is retained even when the mother- cells are moved back- 

 ward and forward in the water under the microscope. The sepa- 

 ration of the secondary cells from each other is however very 

 variable in regard to distance. 



Now commences a new process in the history of the formation 

 of the secondary cells, relating to their form. They do not, like the 

 spores of other Lycopodiacea, remain tetrahedro-spherical, but 

 become elongated (PI. VI. fig. 13) and form bean-shaped cells. 

 On the ventral surface, i. e. on the side of the tetrahedral junc- 

 tion, occurs a double border [Leiste] in a straight line, whence it 

 appears as though the interior of the cell was open (figs. 15 — 25). 

 The border however does not extend the whole length of the cell, 

 but at most f rds or f ths of it. 



This mode of formation of the spores is so much the more 

 striking, that it is in Ferns alone, for instance in Polypodium 

 Dryopteris, that we find anything exactly corresponding. At the 

 same time it appears to me, that it already entitles us to give the 

 hycopodiacece a higher place than, for instance, Schleiden is in- 

 clined to do, who rather places them (Grundziige, ed. 1. part ii. 

 80) in the vicinity of Mosses and Hepatica. However, as 1 have 

 said, more on this matter hereafter. 



The bean-shaped cells lie for some little time in the mother- 

 cell, only, repeating the former condition, they soon become 



