466 BOTANICAL GAZETTE [December 



while the latter is in metaphase (fig. 140), or the upper is left 

 behind in the resting state while the lower is in anaphase (fig. 139). 



may 



middle 



(fi 



Cell divisions continue up to a 12-22-celled stage (figs. 144 



146). 



does 



normal 



is branched. After repeated divisions there is formed a some- 

 what upright structure, not columnar, but rather laterally pro- 

 duced and in irregularly massed lumps (fig. 11, a). This upright 

 structure with a lateral uneven mass consisting of about 35 

 cells is produced in 30 days. The irregular nature of this struc- 

 ture is still seen in sporelings of 50 days (fig. n, b). Some of the 

 irregular appendages of the structure which happen to be in con- 

 tact with the substratum become creeping expansions and later 

 become the main part of the spore] ing. 



And 



the 



(figs, n, c, d)> and the product 



some 



from a fertilized gamete. Comparing these two products, the 



marked 



(1) the first segmenta- 

 te normal sporeling; 

 ?s is verv much slower 



normal sporelings; (3) unfertilized sporelings are char- 



masses 



and even 



assumed 



form massed appendages: (a) the number 



somes is unchanged, the sporeling from the unfertilized gamete 

 containing only 24 chromosomes. 



Aglaozonia rep tans 



MITOSIS IN THE VEGETATIVE CELLS 



Aglaozonia reptans Crouan has a creeping crustaceous habit 

 on rock or sea-urchin's shells, attached by rhizoidal holdfasts from 

 the superficial layer of the ventral surface. The superficial layer 

 consisting: of small cells of ennal si™> is nthf>r «Jnalp (tier, ta?) or 



