242 Mr. R. J. Ludford and Dr. J. B. Gatenby. 



spindle ; in other words, according to Lenhossek and such workers, the 

 centrosphere does not divide as we have drawn in Plate 17, figs. 1-7, of 

 the present paper. But in our own preparations of the rat, we never 

 definitely found such an undivided centrosphere at metaphase, and can only 

 conclude that Lenhossek is wrong. Our figures 1-7 of the rat are carefully 

 drawn and are typical of many examples we have studied. 



In molluscs the Golgi rod or dictyosome is evidently a compact and 

 definitely shaped body possibly formed of some proteid substratum, but in 

 the case of the mammalian germ cell the Golgi element appears to be more 

 fluent, and less able to keep its shape during dictyokinesis. That this is so, 

 seems all the more likely from evidence procured by examining the results of 

 different fixing techniques on the apparatus. The Golgi apparatus dictyosome 

 of the mammalian germ cell during the metaphase always appears to show a 

 tendency to become spherical or ovoid, which indicates that it must be 

 nearly of the same viscosity as the ground cytoplasm in which it lies, 

 assuming of course that the protoplasm is still a sol at this period. 



Chambers' work on the dividing sea-urchin's egg may not apply to 

 maturing germ cells, but we do not know at present. At all events it seems 

 indicated that the Golgi substance of the mammalian germ cell is of a more 

 liquid nature than that of the mollusc. 



There is then another matter to which we wish to turn : although many of 

 the older workers figured Golgi rods or dictyosomes in the resting cell, they 

 rarely found any apparatus during kinesis. Take for instance the work of 

 TuUio Terni.* 



It is quite certain that some change comes over the Golgi elements during 

 cell division ; in molluscs, insects and mammals, in certain worms such as 

 S'accocirrus, and in all the examples we have observed, it has been found that 

 it is possible to find mitoting and resting cells side by side, in either of which 

 the apparatus may apparently be absent — but only apparently. 



The case of the mollusc spermatocyte is classical ; short mordanting in 

 chrome osmium, and curtailed staining in iron haematoxylin is always 

 sufficient to show the Golgi rods of resting cells, but this treatment will often 

 prove insufficient to bring into evidence the apparatus of mitoting cells. 

 But prolong the mordanting, and the staining, and the story becomes quite 

 different — this is what observers like Terni have failed to do. 



To explain this behaviour of the Golgi element is difficult, yet in it we see 

 possibly the one solution. In the case of the chrome osmium technique it 

 seems that the difference is due to a withdrawal from the Golgi elements at 

 the prophase and metaphase, of some lipoid substance to which the heavier 



* 'Arch. f. Zellf.,' vol. 12 (1914). 



