CELL-MULTIPLICATION IN A SPECIES OF ENTEROMORPHA. 559 
Figs. 11, 12, 13, 14. Showing colourless shoots of various sizes. 
Fig. 15. 
Fig. 16. 
Colourless shoot acquiring chlorophyll. 
Frond in which colourless cells are irregularly developed among green cells. 
Figs. 17, 18. Fronds in which such irregularly interposed colourless cells have greatly multi- 
Fig. 19. 
Fig. 20. 
plied, so as to push the original green parts of the frond far asunder, and to produce 
the appearance of green shoots arising from a white frond. 
Gemmation of colourless cells from green very clearly shown. 
Shoot in which green cells are sending out colourless processes, probably incipient 
buds. 
Figs. 21, 22, 23. Apical colourless shoots of various sizes. 
Fig. 24. 
Fig. 25. 
Shoot similar to fig. 23, developing chlorophyll. 
Tip of frond of which the two terminal green cells have been carried up by the 
development of a colourless shoot below them. 
. Frond with apical white shoot. 
. Mode of origin of colourless from coloured cells very clearly shown (see 
figs. 4 and 19). 
. Colourless shoot developing chlorophyll, bearing already a lateral colourless bud. 
. Similar lateral colourless bud farther advanced. 
. Showing probable mode of formation of such lateral colourless buds by displacement 
of a cell. 
. Tip of colourless shoot showing its cells in process of division. 
. Frond entirely destitute of chlorophyll save two basal cells. 
VOL xXx, PART Lb: yome 
