22 Mr. H. J. Carter on the Development of the Root-cell 



nucleoli into which the nucleolus divides, I am ignorant ; whether 

 they become absorbed,, or whether they escape from the nucleus 

 into the rotating protoplasm. Judging from what takes place 

 in the cell of the plant-stem, the latter would seem to be their 

 destination ; but, whatever it may be, all trace of them ultimately 

 disappears in the remaining portion of the nucleus. 



Thus far, then, we have seen, that the second root-cell and 

 rootlet-cell developed from the first root-cell correspond, in de- 

 velopment, with the first cell of the plant-stem and root-cell of 

 the embryo-sac. Moreover, when the second root-cell is pro- 

 longed, it undergoes the same changes as the first cell, by which 

 repetition we seem to get further confirmation of what goes on 

 in the embryo- sac before germination becomes evident. All that 

 takes place previous to this, however, is completely shut out from 

 us by the black, opake colour of the middle coat of the nucule, 

 which causes the early part of germination to be as invisible as 

 the glassy transparency of the cell-wall of the root renders its 

 development apparent. Hence, for all that occurs antecedently, 

 we must be guided by inference, and for views on this part of 

 the subject, I can refer the reader to no higher authority than 

 A. Braun, whose observations on the " Nucleus of the Cha- 

 raceaj" are among the papers which have been so happily selected 

 and translated for the advancement of botanical science by 

 Prof. A. Henfrey*. I would here, however, casually notice, that 

 the embryo-sac which turns blue under the action of iodine and 

 sulphuric acid before germination, ceases to do so after the latter 

 has commenced. 



It may now be asked. What becomes of the nucleus when it 

 disappears ? In reply to which I can state no more than I have 

 already done, — viz. that all it leaves behind is a clear space, cor- 

 responding to the form and size of its capsule or cell- wall, with 

 some faint amorphous tissue in the centre, and that this space 

 also soon becomes obliterated or filled up by the fixed protoplasm, 

 after which no trace of the nucleus remains. Its coming into 

 sight again, with its counterpart too, is so faint, that it seems 

 almost hopeless to endeavour to trace the changes between its 

 disappearing and reappearing again, — reduced in size and with 

 double nucleoli, as I have before stated. But this is certain, 

 that one part moves towards the free end of the root-cell, viz. 

 the secondary nucleus, and the other part, viz. the primary part, 

 retires from it, while the septum is formed between the two in 

 the lighter space of the fixed protoplasm originally occupied by 

 the primary nucleus before its disappearance. It is also worthy of 

 remark, that the part intended for the primary nucleus generally 



* Ann. and Mag. Nat. Hist. vol. xii. p. 29/, 1853. 



