Phosphorescence of Zoophytes. 171 
liant little star, and for a short time the polypidom became 
like an illuminated city. 
After some days, I repeated the experiment with other zoo- 
phytes, and with similar success. A third time I brought 
home a well-filled vasculum ; but as I happened to be other- 
wise occupied, it was allowed to lie unopened for five or six 
days, when, thinking that the zoophytes would be dead, I cast 
them out along with the sea-woods to which they were ad- 
hering. They lay in the open air for a night and a day, and 
as it rained heavily during the whole time, weeds and zoo- 
phytes were constantly drenched. When the second night 
had set in, I thought I would try whether there were any 
symptoms of remaining life. I shock Laomedea geniculata, 
but its tiny fires were quenched. Membranipora stellata light- 
ed up just one bright star ; and FVustra membranacea shed one 
faint gleam of light, and refused to repeat the fire, however 
much shaken. 
About a week after, I brought home a fresh supply ; and on 
repeating the experiment, not only did the zoophytes sparkle, 
but my fingers in handling them became brilliant, being adorn- 
ed with little stars. 
The next time I made trial of these ‘‘ minims” was in the 
end of October, when a very frosty morning had been suc- 
ceeded by avery sunny day. On that occasion Sertularia po- 
lyzonias, Cellularia reptans, Flustra membranacea, and Mem- 
branipora stellata would emit no light. As the specimens had 
Jain for hours on the shore exposed to the morning frost and 
the mid-day sun, it is probable that the polypes were dead. 
Laomedea geniculata was taken up quite moist and fresh, ha- 
ving been covered with sea-weeds ; and when the darkness of 
evening came, not only did they brightly sparkle when roughly 
handled, but they emitted a strong smell of phosphorus. On 
being allowed to rest, they immediately ceased to be luminous ; 
and though, on being shaken or pressed with the fingers, they 
shone forth again, if often repeated the light became fainter. 
On this occasion I made an experiment with a creature be- 
longing to another department. Having found a very large 
specimen of Botryllus Schlosseri, one of the Mollusca tunicata, 
I subjected it to the eaperimentum crucis by shaking it roughly 
in the dark, and I had the satisfaction of seeing that it was as 
