1903-4.] On Aged Specimens of Sagartia troglodytes, etc . 305 
Anthozoa. 
(1) Actiniaria . — The instances given earlier in this paper show 
that the age at which an anemone becomes mature varies with the 
species and conditions. For example, Dalyell (p. 217) records a 
specimen of Actinia mesembryanthemum , one of the progeny of his 
famous specimen, which was mature fifteen months after its birth ; 
while M‘Bain (p. 287) states that another of the progeny of this 
same parent, although carefully tended and fed at least once a week, 
was four years in reaching maturity. Sagartia troglodytes seems 
to be at least three years in reaching maturity, at any rate in 
captivity. These anemones may continue productive, either 
regularly or at intervals (this being apparently largely determined 
by the external conditions and regularity of feeding), for over 
fifty years. The only information available respecting the actual 
duration of life in anemones is that derived from the statement 
that Dalyell’s Actinia apparently died u a natural death ” at the 
age of sixty-six (see p. 302). Miss Nelson’s specimens of Sagartia, 
which are now about fifty years old, show little sign of loss of 
vegetative vigour, but, as noted above (p. 300), breed either 
sparingly or not at all. 
(2) Madreporaria . — The only reference known to us upon the 
duration of life in corals is contained in a paper by Mr Stanley 
Gardiner (1902). He describes (pp. 465-468) the life history of 
Flabellum riibrum , and states that by the time the corallum 
measures 15-17 mm. along the long axis of its calicle, the 
mesenteries bear testes, and spermatozoa are being discharged 
from those on the larger mesenteries. Coralla of this size bear 
“ five lines of growth, which correspond probably to annual 
periods.” Later, the male organs gradually disappear and ova 
are found on the mesenteries. In specimens in which the axis 
of the corallum is over 25 mm. in length, ripe ova are present. 
As the two or three large ova on each mesentery are extruded, 
a similar number of smaller ones take their place, and this 
and a substance which they call by the name of a coin of money as broad and as 
round as a groat, wonderfully printed and stamped of nature like unto some 
coinP — ■ Voyages and Travels, mainly during the Sixteenth and Seventeenth 
Centuries, C. R. Beazley, 1903, p. 158. 
PROC. ROY. SOC. EDIN. — YOL. XXV. 
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