584 DR. J. B. HICKS ON THE GONIDIA AND 



covered with Moss of equal-sized growth. It is also to be remembered that, amongst the 

 Cryptogamia, it is in the Mosses that they assume the most important position. They 

 are known at present in only three divisions, viz. in Ferns, Liverworts, and Mosses. In 

 the two former they are confined to a very small number of short-lived cells. 



But it is when they are considered in combination with their gonidia and their 

 indefinite powers of subdivision (only comparable to the Lichens in this respect) that we 

 can appreciate the influence they possess in multiplying the Mosses, accounting, doubt- 

 less, for their well-known abundance and wide diffusion ; and this brings me to another 

 consideration in relation to the reproduction of Mosses by their means. 



I have shown above, that the cells thrown oflF from the filaments, as also those that 

 remain attached, multiply by subdivision on the binary or quaternary plan princi- 

 pally (parietal cell-formation), and also that both within these cells when separated, 

 as well as in those still attached, cells were formed (free-cell formation) which again 

 continued to subdivide. By these processes and their continuation innumerable myriads 

 of cells are produced, wliich possess all the appearances assumed by the results of the 

 same efforts in the Lichen-gonidium. At first, I remarked, the contents of the cells were 

 granular, but soon became homogeneous and without perceptible nucleus. Thus forms 

 of segmenting cells hitherto classed as Chlorococcus (Protococcus) and Gloeocapsa 

 (JEwmatococcus) are produced undistinguishable from those so-called Algse ; so that, 

 considering the exceeding diflJ'usibility of the Mosses and Lichens alone, it seems to me 

 to be almost impracticable to declare that any of these forms, as well as those I have 

 mentioned in my paper on the gonidia of Lichens (above quoted), have an independent 

 existence as Algse. 



On the contrary, it seems to me impossible to discriminate between the cells of the 

 segmenting gonidia of Algae*, of Lichens, and of Mosses ; and hence I believe we shall 

 be obliged to conclude that all the cells classed as Palmellacese — Chlorococcus, Gloeocapsa, 

 Sorospora, and some others t, with their so-called species — are but varieties of one mode 

 of simple vegetative cell-growth, common to most of the Cryptogamia. What is the 

 value of the differences between each kind it seems diiScult to decide, but it may pos- 

 sibly be less than hitherto supposed. 



Without digressing far into a subject not here intended to be discussed, I shall content 

 myself with pointing out the effect such an opinion produces in unsettling our belief in 

 the reality of the separate existence and position of the Protophytes generally, more 

 particularly those classed by Braun as pseudo-uniceUuIar AlgseJ. Whether it affects 

 Braun's true unicellular Algae requires further investigation; but it is worthy of notice 

 that it is in the former that the forms above named are arranged. 



4. The chlorophyll-utricles next arrest our attention. I have already quoted NageH's 

 remark upon their segmentation, in which opinion Henfrey, in Linn. Trans, vol. xxi. pt. 2. 

 p. 121, coincides. But in regard to their cell-wall, difference of opinion exists. The 

 observations I have here recorded, it appears to me, tend to explain the two opinions, 

 and especially confirm the opinion expressed by the writer of the article on Chlorophyll, 



* See Priugsheinij Mic. Journ. 1862, April, p. 105. 



f Probably also Tetraspora and Hormospora. J Mic. Journ. 1857, p. 13. 



