and its Nucleus in Chara verticillata. 17 



nucleoli (fig. 5 d). When the second or following root-cell be- 

 comes terminal, that is, ceases to throw out any more cells, 

 the nucleus, after the breaking down of the fixed protoplasm, 

 moves about for some time before it becomes fixed ; and this is 

 effected partly by the rotating protoplasm and partly by its own 

 locomotive power, which at this time is particularly evident, from 

 gradual change of form while under observation. I have stated 

 that the " nuclear utricle " and its contents are transparent, but 

 this is only in comparison with the turbid fixed protoplasm in 

 which it is imbedded ; for when it gets into the clearer cavity of 

 the rotating protoplasm, it not only presents a cloudiness inte- 

 riorly, but, a certain time after it has become stationary, also 

 becomes filled with vacuoles (fig. 12 a), like those which will be 

 found to be developed in the fixed protoplasm preparatory to its 

 assuming a more attenuated form and mingling with the rota- 

 tory part. In short, this is the last vital phsenomenon presented 

 by this organ ; after which it passes into an effete amorphous 

 piece of tissue like cellulose (fig. 6 d). 



Round or " irregularly shaped bodies." — These are small opake 

 yellowish masses of protoplasmic (?) matter (fig. 2 e, e, e), irre- 

 gularly scattered throughout both the fixed and rotating proto- 

 plasm, and seem to be the same as those which I have described 

 under this head in giving an account of the contents of the pro- 

 toplasm of the internode of the plant-stem, but they never grow 

 large enough to arrive at those fantastic shapes which are found 

 in the latter*. Like these, also, they are frequently seen ap- 

 pended to, or in the w all of a globular mucus-cell (fig. 14^, b); and 

 this cell may be transparent or clouded by the presence of mole- 

 cular mucus, while it also frequently manifests a power of move- 

 ment. Many of these bodies have very much the appearance of 

 the small nucleoli into which the primary nucleolus divides, but 

 as they appear in the cell before the latter takes place, this can- 

 not be their origin. 



Granules. — Lastly we come to the granules (fig. 2/, ^'c), which 

 are of much interest, on account of their being grouped together 

 in one part of the cell only, their marked characters, and their 

 incessant oscillatory motion. They are situated in the fixed pro- 

 toplasm close to the free extremity of the cell-wall, and are 

 recognized by their dark margins, greenish colour, constant 

 motion, and tendency to keep together in a group. At first they 

 are round or elliptical (fig. 15 a), and of the tint mentioned, but 

 after a while they become subrotund or angular, and colourless {b) 

 — apparently effete. When thefixedprotoplasm begins tobe broken 

 up by the development of vacuoles, they are seen to be scattered 



* Ann. and Mag. Nat. Hist. loc. cit. p. 106, &c., pi. 8. figs. U-13. 

 Ann. ^ May. N. Hist. Ser. 2. Vol. xix. 2 



