50 Ml Allan E. Grant on the 



among the latter tu be correct. Six out of the eiglit plants 

 examined by me were Dicotyledons. 



Part III. — Some Points in the general Mmyhology of 

 the Cell. 



The older cells do not afford much evidence of the 

 arrangement of the protoplasm in a definite intercellular 

 network, such as is seen in the young actively growing cells. 

 The nearest approach seen to it is the mooring of the 

 nucleus to the cell-wall, sometimes much as in Spirogyra. 

 Another point is the dift'erence in shape of the nuclei in 

 the various cells. To this I have alluded before^ and 

 stated that I believe it to be due to the difference in 

 shape of the cells, and to the " dragging " of the proto- 

 plasm, in the course of its circulation, upon the nucleus. 

 The nuclear membrane was often very distinct indeed, and, 

 in fact, could almost always be made out. I also frequently 

 saw that the nucleolus also was bounded by a distinct 

 limiting membrane. 



I have also alluded before to the existence of a curious 

 hyaline circle of protoplasm in the body of the nucleus at 

 times, this being particularly seen in large hypertrophied 

 nuclei.* The independent and important characters of the 

 nucleolus and endo-nucleolus seem now fully established, 

 and there would seem to be no reasonable doubt that 

 division of the endo-nucleolus institutes the act of division, 

 whether direct (as I have observed) or indirect. 



One remark as to the production of the multinucleated 

 condition of the cell artificially, I believe that a series of 

 more extensive experiments, conducted somewhat on the 

 lines of M. Prillieux's, would conduce greatly to establish- 

 ing the hypothesis advanced by Dr Macfarlane. 



* With regard to this h5'aline circle of protoplasm in the nucleus, the 

 following occurs in the last edition of Quain's Anatomy (1882), vol. ii. p. 10 : 

 — "Eimer describes a more complicated arrangement as existing in many 

 nuclei, in the form of a clear 'hj'aloid' zone, encircling the nucleolus and 

 bounded by a circlet of granules, which are united ^vith the nucleolus by fine 

 radial filaments. It is difficult to avoid thinking that the appearance 

 described by Eimer must be mainly an optical effect produced by reflection 

 of light from the sides of the nucleolus. " Although I have not noticed the 

 " fine radial filaments " spoken of, I have often seen the so-called "hyaloid 

 zone," and can only conclude from the latter remark of the editor of Quain 

 that he has never seen the appearance indicated. 



