374 



CELL-DIVISION AND DEVELOPMENT 



I believe there is reason to accept the conclusion that this relation 

 is one of position, however caused. A central position of the mitotic 



Fig 175 - Embryos of the earthworm Allolobophora fc.tida, showing teloblasts or apical cells. 



A. Gastrulafrom the ventral side. B. The same ^^--\''--'-^^\i^^'^l':f^^^^^^ 

 blasts or /r.;«a.;^.«...^/a./.. which bud forth the mesoblast-bands. cell by cell , ^- 1;^^^^^^ 

 comprising a nuroblast, nb, from which the ventral nerve-cord anses and two -{f ^^^^^^^ ^^^ 

 ^mewhat^doubtful nature, but probably concerned in the formation of the -Phnd^- <=' Patera 

 group of teloblasts, more enlarged, the neuroblast, nb, m division; u. the nephioblasts. 

 primary mesoblasts enlarged; one in division. 



fio-ure results in an equal division ; an eccentric position caused by a 

 radial movement of the mitotic figure, in the direction of its axis 

 toward the periphery, leads to unequal division, and the greater the 



