AROHOPLASM DURINC4 MITOSIS IN LAEVAL SALAMANDER. 183 



It is not clear whether the archoplasm is more especially 

 related to reproductive cells, or is a normal constituent of 

 the resting sphere, though often masked by individual 

 specialisation. 



It is not known whether the immediate relationship exist- 

 ing, according to Platner, between the disappearance of the 

 " Nebenkern " (archoplasm of Boveri and van Beneden) 

 and the generation of the spindle, is found elsewhere than 

 in the cells of Helix ;^ although the last results of Her- 

 mann, in his work on the spermatocytes already referred 

 to, is, at any rate, not antagonistic to a belief in its ex- 

 istence. 



A series of observations on the conditions of these various 

 bodies and zones in several tissues of the larval salamander, 

 most notably the undiflferentiated genital ridge and the leuco- 

 cytes, have not only enabled me to arrive at definite con- 

 clusions respecting the above relationship of archoplasm and 

 spindle, but, by the powers of the beautiful process of research 

 inaugurated by Hermann, have thrown considerable light on 

 the foregoing confusions. 



In salamander larvse, taken while living from the parent, 

 fixed with the platinum chloride solution, reduced with 

 " Rohen Holzessig,'' cut and examined without further pre- 

 paration, after the manner of Hermann, the archoplasm 

 (" Nebenkern, ■"' '' sphere-attractive") was beautifully difi'eren- 

 tiated in the cells constituting the embryonic genital ridge 

 (figs. 1, 3, 4, 7, 8, 16) as a pale grey round or oval mass, as 

 sharply circumscribed as, and often not much smaller than 

 the nucleus itself (figs. 5, 7, 4, 8). 



When most conspicuous, however, the archoplasm is rela- 

 tively small (figs. 13, 16, 14), and in this condition presents, 

 even with the highest power, only doubtful suggestions 

 of "medullary zone" or central body, and there are good 

 grounds for believing that in some conditions of the cell^ 



1 See Platner's second paper " Zur Bildunj? der Geschlechtsprodukte bei 

 den Pulmonaten," • Archv. mikr. Anat.,' Bd. xxvi, p. 604. 

 Mnfra, pp. 194, 195. 



