ON THE MODE OF GROWTH OF SOME OF THE ALG/E. 
9 
Fig. 1. 
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11 . 
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15. 
16. 
17. 
DESCRIPTION OF PLATE. 
Simple cell — a, cell-wall ; b, green contents ; <?, nucleus. 
One of the cells of the froud of Drapamaldia cruciata — showing 
hand of chlorophyl at equator. 
Pollen on stigma — a, pollen-grain ; b, b, tubes extruded from it ; 
c, cells of the stigma. One of the tubes can he seen entering 
between. 
Antherozoids. 
a , antheridia of bladderwrack ; b, cells in which the antherozoids 
are produced j c, free antherozoids ; d, one of the spores. 
End of tube of Vancheria Ungeri — a, first stage of spore-forma- 
tion j b, escape of spore 5 c, matured spore covered with cilia. 
Impregnation of spore of Yaucheria — a , antherozoids escaping 
from the antheridial process ; b , spore enclosed in the other pro- 
cess ; which is open to admit the antherozoids. 
Spirogyra quinina. 
One cell of same ; showing the stellate nucleus. 
Same plants — a, conjugation of two filaments \ b, free spore. 
Zoospore — formation in same. 
Cylindrocystis JBrebmonii — a shows nucleus of simple cell ; b } two 
cells, having conjugated, have formed a spore. 
Lyngbya — a, gonidium. 
Same, growing. 
Same, recurring to filamentous form. 
Same, throwing off cells which are dividing. 
Divisions of the gonidium at 14, a. 
