3.2 M. Miiller on the Development of the Lycopodiacese. 



tion of the oolite limestone or urinary calculi, &c., the nucleus 

 of which is a granule, which is afterwards to be found in the 

 centre. This analogy is the more striking here, since in these 

 amylum-cells the contents have been likewise deposited concen- 

 trically around the nucleus, as in these crystalline formations. 

 Some authors draw a parallel between the processes of cell-for- 

 mation and crystallization, and in fact I see no reason to object 

 to this view. 



From these observations this cell-formation appears to be 

 somewhat different from the usual kind depending on cytoblasts. 

 Here we have no cytoblasts but only a simple nucleus as a cen- 

 tral organ ; around this the protoplasma is deposited till the 

 outermost surface hardens ; in the other formation, protoplasma 

 is indeed similarly deposited round a nucleus and so forms the 

 cytoblast and through this a cell, but then the process is of some- 

 what longer duration, as the outer surface of the cytoblast must 

 first become softened and extended to form a membrane, while 

 in the other case such solution and extension does not take place, 

 and the outer surface of the protoplasma is immediately trans- 

 formed into '^ membrane substance.^^ Thus we can, if we like, 

 with perfect right in our case, call the cells cytoblasts which de- 

 velope directly into cells, since they soon become hollow, although 

 the protoplasma is not perceptible without the addition of iodine. 

 As a whole however it comes to the same thing, with this di- 

 stinction only, that in one case the protoplasma is not precipitated, 

 as in the cytoblast, in the form of a granular and distinctly vi- 

 sible, compact mass. In both cases the nucleus is to be consi- 

 dered as the central organ, as therefore especially the basis of 

 cell-formation. The cells now become hollow by the absorption 

 of the protoplasma. This does not take place quite completely 

 at first, for, exactly as in the cytoblasts, the nucleus comes to be 

 suspended in the centre by thin, persisting filaments of proto- 

 plasma, till at last both filaments and nucleus disappear. 



Thus these observations wholly agree with MohFs so far, as 

 here the protoplasma is deposited round the nucleus exactly as 

 he describes. The formation of membrane alone by the direct 

 hardening of the outer surface of the protoplasma deposited round 

 the nucleus appears to be a new modification of cell-formation. I 

 am the less inclined to believe myself deceived here, since I could 

 never find any true cytoblasts, and I saw that the cells were 

 already filled with protoplasma in their earliest stage. I must 

 particularly remark, that the earliest cells inside the spore cer- 

 tainly originate independently. I never found secondary-cells 

 within parent-cells. 



This formation of cells commences at a particular spot on the 

 inner spore-membrane. The spot is characterized by the fact 



