12 SUMMARY OF CURRENT RESEARCHES RELATING TO 



in diverse cells. The chromatin is diffused through the whole resting 

 nucleus ; though found chiefly in the nucleoli, plexus and membrane, 

 it also exists in the intertrabecular substance. The adjectives 

 chromatic and achromatic explain themselves. Division of nuclei is 

 indirect wherever accompanied by metamorphosis of the nuclear mass 

 into filaments ; it is direct if there be no such metamorphosis. Both 

 these terms are provisional. Flemming proposes to drop them as 

 superfluous, should it at length be shown that but one (indirect) mode 

 of division occurs. He would extend the expression haryohinesis, 

 introduced by Schleicher and adopted by Strasburger, to all movements 

 or changes of position undergone by the nuclear filaments during 

 division. Schleicher accepts this extended meaning. Flemming 

 objects, however, to Schleicher's occasional use of " amoeboid " as a 

 synonym for karyoJcinetic. The latter word is preferable, as indicating 

 the mere occurrence, and not also the supposed cause, of the nuclear 

 movements ; as to which cause, we cannot say whether it be intrinsic, 

 extrinsic, or mixed. " Amoeboid," like " contractile," is rightly ap- 

 plicable to those changes of form whose proximate cause lies in the cell 

 itself. Moreover, the irregularity of amoeboid movements strikingly 

 contrasts with the almost isochronous and much more definite trans- 

 formations of the nuclear filaments. Nuclear figure, and not " karyo- 

 kinetic figure," is Flemming's term for all phases which the nucleus 

 assumes during division. Strasburger, accepting the same phrase, has 

 applied it to tlie middle stages (spindle or barrel figures) only. The 

 terms coil {Knduel, also Korh or basket), star, and equatorial plate 

 indicate the principal phases of division, respectively. 



That such definite phases appear and recur with much regularity, 

 although not always manifested in the same distinct manner, among 

 various animal and vegetable cells, is now probable. Such is the 

 thesis maintained by Flemming in his first Section, along with the 

 proposition that indirect division has been proved to be of very 

 general occurrence. Moreover, in appreciating these truths, their 

 physiological no less than their morphological significance must be 

 considered. This being so, we are able to avail ourselves of the 

 ready means of demonstration which the large and more easily 

 examined cells of batrachians (amphibians) present, in comparison 

 with cells whose smaller nuclei need the use of higher powers, and 

 afford, save under unusually favourable circumstances, but occasional 

 glimpses of the phases we seek. The new objects which are here 

 reviewed and figured are chiefly taken from the tegumentary and 

 testicular epithelium of the Salamander ; but ten figures are added 

 from plants (endosperm of Nothoscorodon fragrans and epidermis of 

 pistil in Allium odorum), affording data for a discussion of some of 

 the results of Strasburger, besides a few others from the oral 

 epithelium of the tadpole, the omentum of the kitten, and the ova of a 

 sea-urchin (these last after preparations by H. Fol). In the same 

 connection Flemming notices those writers who support or partly 

 contradict his views, and cites several in addition to those mentioned 

 in his former papers.* 



* Part I., and in Virchow's Arch., Ixxvii., Marcli 1879. 



