THE HIGHER CRYPTOGAMIA. 145 



which has the appearance of a bright circle, is surrounded 

 by an apparently homogeneous, pale greenish mucilage. 

 The intensity of the green colour increases towards the 

 apex. In cells which are about to divide, the formation of 

 two nuclei, in the place of the primary one which has dis- 

 appeared, precedes the formation of the transverse septum, 

 as is the case generally in the higher plants ; but, besides 

 this, the green mucilage divides into two globular masses, 

 each of which surrounds one of the newly formed nuclei 

 (PI. XVIII, fig. IS). Higher up, in cells whose multipli- 

 cation has ended, the nucleus is no longer seen, but two 

 large chlorophyll-bodies are found in the cell-cavity, in the 

 interior of which bodies some starch-grains occur (PI. XVIII, 

 fig. 19). In the cells close to the apex of the leaf, whose 

 walls have already become thick, the number of chlorophyll- 

 bodies amounts to four, six, eight, or even more. The 

 appearances which are seen during the formation of the 

 chlorophyll-bodies in the leaves of Sphagnum and of P/ias- 

 cum cuspidatum are essentially the same as those observed 

 in Fissidens. In leaves of Sphagnum where the division 

 of the cells into three parts has extended as far as the base, 

 and at whose apex the last active process (viz., the differen- 

 tiation of the cells into those with, and those without, chlo- 

 rophyll) has occurred, the cells of the base of the leaf are 

 found to be quite filled with finely granular, yellowish green 

 protoplasm, within which the nucleus appears in the form 

 of a bright circle. Somewhat nearer to the apex of the leaf 

 this protoplasm exhibits numbers of immeasurably small, 

 dark-green particles, not individually distinguishable, by 

 which the protoplasm is rendered turbid. 



Hitherto all the cells of the leaf develope themselves 

 equally. Towards the apex, however, the coloured matter 

 within the quadrate cells diminishes more and more until 

 it disappears altogether, whilst in the oblong cells it appears 

 suddenly conglomerated into one or two spheroidal masses 

 or chlorophyll-bodies. Nearer still to the apex of the leaf 

 the chlorophyll-bodies in the oblong cells increase in number 

 and diminish in size ; this is manifestly caused by the divi- 

 sion of the existing bodies, inasmuch as some of them may 



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