CHONDRIOSOMES IN CELLS OF FISH-EMBRYOS 479 



Both jNIeves ('10, 1) and I ('10, 2), independently, reported 

 later that certain changes may occur in the chondriosomes dur- 

 ing the division of the embrj^onic cell of the chick, especially in 

 later stages than those first studied by Meves. The chondrio- 

 somes are very often found, during the ana- and telophases, 

 accumulated between the daughter-nuclei, whilst their shape, 

 size and number appear to have changed during the mitotic pro- 

 *cess (cf. Meves, p. 154 and Duesberg, p. 616-617). Such modi- 

 fications exist also in the dividing cells of the fish-embryo. The 

 accumulation of chondriosomes between the daughter-nuclei 

 has been mentioned above, in connection with the description 

 of the blastomeres of Fundulus, and the phenomenon is well 

 illustrated by the dividing blood-corpuscles represented in 

 figure 4b. The same figure shows also the longer filaments con- 

 tained in the blood-corpuscles broken to pieces during mitosis. 

 Both processes result obviously, as Meves and I (loc. cit.) have 

 indicated for the chick, in an apparently equal repartition of 

 the chondriosomal substance between the daughter-cells. 



Concerning their studies of the chondriosomes in the dividing 

 cells of the chick-embryo in tissue-cultures, M. R. and W. H. 

 Lewis ('15) write: 



Many observers believe that the mitochondria form a palisade about 

 the spindle during late anaphase and then divide and one-half of each 

 mitochondrium passes to each daughter-cell (Benda, Meves, Duesberg, 



etc.) (p. 365) A study of the fixed specimens seems to 



show that the mitochondria retain somewhat their original character 

 and shape during mitosis. They are however almost always shorter 

 and more scattered through the cytoplasm, than in surrounding cells. 

 . . . . There is no indication in the fixed specimens of any ar- 

 rangement of the mitochondria about the spindle in such a manner 

 that they would undergo division into two parts in the plane of cleav- 

 age of the dividing cell. On the other hand, all of our specimens seem 

 to show that the mitochondria tend to become more evenly scattered 

 through the cytoplasm during division, and those that happen to be 

 on either side of the cleavage plane are carried into the respective 

 daughter-cells (p. 366). 



The same description is repeated on page 371 in connection 

 with the Uving cell and the authors add: ''A division of mito- 

 chondria such as observed by Meves ('08) and Duesberg ('10) 



