Besa, 
334 BOTANICAL GAZETTE [Novewsen 
numbers of fruiting tips in the different dishes. At the same time 
I similarly prepared four dishes of Cystoseira erica marina. In two 
hours and three quarters there were evidently many more spores 
(eggs) in the lighted dishes of C. erica marina than in those in the 
dark, but apparently about equal numbers in the two sets of dishes 
of C. barbata. At about 10 o’clock the next morning I removed the 
branches of C. erica marina from the dishes, throwing away those 
that had been kept in the light, and poured off the water from the 
four dishes. I counted 99 and 50 eggs in the two dishes which had 
been kept in the dark, 454 and 420 in the dishes kept in the light. 
The latter two had of course been dark for nearly or quite twelve 
hours, from sunset to sunrise. The branches which had been in the 
darkened dishes I put back in these dishes, with fresh sea-water, and 
set them on the window shelf. Four hours later many eggs had come 
out and I therefore removed the branches, but left the dishes quiet 
till the morning of the 1oth, so that the eggs might settle and become 
fastened to the bottom of the dishes. On the morning of the roth, 
I poured off the water, preparatory to counting the spores. Many 
spores were carried away by this means, but those attached to the 
bottoms of the dishes now numbered 270 and 241 respectively. 
I made similar counts of the number of eggs of C. barbata 
and attached in the dishes darkened for twenty-three and one-half 
hours. There were 426 and 348 in the two darkened dishes. There 
were so many spores in the dishes which had been exposed wae 
daylight till sunset and after sunrise that I contented myself fa 
counting those in the first three spaces from one side of one dish. # 
this space there were 376 spores. This area equals about oné quart 
the area of the bottom of the dish. The spores were not | 
distributed over the bottom, but there were at least oe 
many over the whole area. There were therefore about four er, 
many spores in the dishes which had been in the daylight as 7 
constantly darkened dishes. As with C. erica marina, I put ad thet 
fruiting branches which had been in the darkened dishes, fl Three : 
with fresh sea-water, and set them on the shelf by the window. oe 
hours and a half later I took out. the branches, leaving t ne 
which had escaped to settle in the dishes and to beT i. 
The next morning I counted the spores attached to the a : 
* 
