CONFERVOID FILAMENTS OF MOSSES. 579 



The next series of remarks will show the results of "free-cell formation^^ (Nageli), or 

 "free cytogenesis " (Pringsheim), as it occurs in these filaments. 



As far as my observations extend, there are two varieties of this mode of cell-formation 

 in this portion of the Mosses. 



1. The first is by the gathering together of the whole contents into one or more oval 

 masses, which become covered by a cell-wall thrown around each portion ; and by the 

 segmentation of these while still within the parent cell (PI. LVIII. fig. 2\a,b,c). In 

 both instances these masses are released by the destruction of the parent-cell wall. That 

 they again divide when set free, probably many times, is all that I have been as yet able 

 to discover, beyond the amoeboid change to be alluded to below. This I have observed 

 best in those cells which have lived in water — a position probably favouring this 

 mode. That these portions of contents can segment, and continue to do so, seems to 

 me to militate entirely against the opinion that the whole process is not a healthy 

 one. 



There is another point in connexion with these new cells, namely, that their contents 

 become of a red or reddish-brown colour, in manner similar to the change so frequently 

 observed among Algae that I need not particularize it here. 



But the most remarkable feature in their history is that upon which I have already 

 dwelt in a paper on vegetable amoeboid bodies (Mic. Journ., April 1862), and there- 

 fore need not do more than call attention to the point, namely, that these cells gra- 

 dually lose their colour, with the exception of a few reddish granules. When this 

 change is complete, they possess the j^oioer of moving about as do Amcehce (PI. LVIII. 

 fig. 22ff, 5). After they have continued to do so a certain time, they reassume the 

 ovoid form, and are clothed with very delicate cilia, in a constant state of vibration 

 (PL LVIII. fig. 22c). Tor further remarks on this curious change, and its connexion 

 with similar occurrences in the Algae, I must refer to the paper above quoted. 



2. The second mode of free-cell formation is as follows : — 



The cells in the stem and leaves of the Mosses contain, as is well known, a varying 

 number of granules of a homogeneous green colour, which are called by Nageli and others 

 "chlorophyll-utricles." They are generally connected with each other by means of 

 delicate colourless threads of endoplast. These utricles or granules are also found in 

 the confervoid filaments, in variable quantity, sometimes, as in rapid growth, widely 

 separated, sometimes, as in slow growth, closely pressed together. 



In either case these chlorophyll-masses have the power of throwing around themselves 

 a cell-wall, of growing, of forming in their centre a nucleus, and of segmenting, and also 

 oi forming an independent cell capable of undergoing further changes presently to be 

 pointed out. 



Now Nageli has already pointed out that they possess an outer membrane, and has 

 shown that they multiply by subdivision*. The fact, however, of their having a new 

 membrane has been denied by Caspary f, Mohl and Gris, and by the author of the article 

 on Chlorophyll, in the ' Micrographic Dictionary,' who, on the other hand, admits of the 



* Ray Society, 1849, pp. 176-178. t Die HydrillEe, Pringsheim' s Jahrb. d. Wiss. Botauik, i. p. 399. 



