CONFERVOID FILAMENTS OF MOSSES. 585 



in the ' Micrographic Dictionary,' namely, that chlorophyll-granules are probably small 

 portions of contents coloured by chlorophyll. If we consider them to be such, and that 

 they are capable of losing colour, or of changing it to brown or red, &c., then it is easy 

 to conceive, and what indeed we should expect, that each granule could proceed to form 

 a cell witjiin the parent cell in accordance with what we know of free-cell formation ; and 

 thus the various opinions expressed upon tliis point are capable of being reconciled. 

 Whether this condition extend to the chlorophyll-granules of Nitella, Chara, &c., I am 

 not in possession of any facts to show. 



5. But perhaps the most interesting fact I have met with in the course of my 

 observations on the filaments is that of the formation of zoospores from these enlarged 

 and segmenting chlorophyll-utricles. I am not aware of their having been noticed in 

 the Cryptogamia above the Algse, though they have been seen in the Eungi. 



The evidence vipon which it is based seems to me at least as conclusive as it is possible 

 to obtain under the circumstances, unless the zoospores were seen to emerge directly 

 from within the cell of the filament. It is possible that future observation may be able 

 to confirm my observation in this direction ; but without that, it seems that we may fairly 

 conclude that zoospores can spring from these cells ; and this is perhaps not quite so 

 surprising a fact as it would at first sight appear, when we reflect that the formation of 

 zoospores is purely a vegetative process and, for anything we know, may be more 

 extensive throughout the vegetable kingdom. 



I have already remarked*, with respect to the diamorphosis of lAjnghya, that the 

 distinction between JJlva and Prasiola was now confined to the supposed fact that the 

 former produced zoospores, while the latter did not. This, I objected, could not be 

 held a sufiiciently distinctive sign, on account of the truly vegetative origin of the 

 zoospores, which are merely a variety of gonidial formation. 



Zoospores seem capable of arising at various epochs in the life of a plant, and of 

 various sizes. An interesting account, as they occur in Sydrodictyon, is given by 

 Pringsheim in Mic. Journ., April 1862. 



It is a very interesting feature, however, to find, that the confervoid filaments of 

 Mosses, which in so many ways present the confervoid type, should also in this show one 

 of the most marked and frequent phenomena of the Algae. 



6. The last point to which I shall allude is the near connexion with the Algfe which 

 the Mosses hold in their capability of producing gonidia from any portion of their stem 

 or leaves. The facts I have brought forward here show a very curious link existing 

 between the Thallogens and the higher Cryptogamia, and prove that the formation of 

 gonidia by no means ends with the Algae. 



* Mic. Journ. suprh cit. 



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