36 
POPULAR SCIENCE REVIEW. 
connecting them with certain special branches. The cystocarps 
are produced on these special fertile branches, and the tubes 
apparently convey the fertilising power from the trichogyne to 
them. The act of fertilisation always consists of a conjugation 
of the roundish antherozoid with the trichogyne, its protoplasmic 
substance passing over into the latter. Sachs compares the pro- 
cess with that which produces the fructification of the Pezizse 
and Erysiphese among fungi. 
The Floridese, like all other algae, contain abundance of 
chlorophyll, which is, however, concealed from view by the red 
colouring substance, phycoerythrine. M. Eosanoff extracted 
this substance by cold water, and examined it accurately. In 
transmitted light it is carmine-red, in reflected light reddish- 
yellow. The grains of chlorophyll also show fluorescence, 
if left behind when the phycoerythrine has escaped in 
consequence of injury to the cells. The whole plant remains 
green when the red colouring matter has been extracted or 
destroyed by heat. Millardet obtained in the same way from 
the Fucacese, by extraction with alcohol, a yellow substance, 
phycoxanthine, and a reddish-brown colouring matter, phyco- 
phaeine, which in like manner conceal the chlorophyll in the 
brown or olive-green sea-weeds. 
EXPLANATION OF PLATE OVI. 
ALG2E : THEIR STRUCTURE A HD MODE OF REPRODUCTION. 
Fig. 1. Stephcmosphcera pluvicilis. 
„ 2. Vaucheria sessilis : (a) young filament producing zoospores ; (5) 
escaped zoospore with vibratile cilia ; (c) branch producing 
reproductive organs ; (d) antheridium emitting antherozoids ; 
( e ) oogonium ; (/) antherozoids, further magnified. 
„ 3. Acetabularici Mediterranea. 
„ 4. Caulerpa tax if olio. 
„ 5. CEdogonium vesicatum ; zoospore ; (a) in motion with vibratile 
cilia ; (bi) at rest. 
„ 6. Spirogyra longata ; (a) cells preparing for conjugation. 
„ 7. Fucus vesiculosus ; frond with fructiferous tubercles (a) and air- 
bladders ( b ). 
„ 8. Fucus vesiculosus ; section of male conceptacle lined with 
branched hairs bearing the antheridia. 
„ 9. Fucus vesiculosus j section of female conceptacle, containing 
sporangia. 
„ 10. Fertilisation of Fucus vesiculosus ; spore surrounded by anthero- 
zoids. 
,, 11. Macrocystis pyrifera. 
12. Lessonia fuscescens. 
from Hooker’s u Flora Antarctica.” 
13. Nemalium multijidum ; (a) male branch, emitting antherozoids ; 
(b) female branch, ending in the trichogyne (c), which the 
antherozoids reach. 
