1903 - 4 .] On Aged Specimens of Sagartia troglodytes, etc. 303 
four years produced over 20 young ones, so that the offspring 
produced by Daly ell’s Actinia when it had reached the age of fifty 
years were quite normal and vigorous. 
A few of the statements regarding the breeding of these 
anemones in captivity may he brought together here. As noted 
above (p. 297), Miss Nelson’s specimens of Sagartia troglodytes , 
which are usually fed once a month, breed in the spring. During 
the spring of this year (1904), however, when they were somewhat 
neglected, and feeding, aeration and change of w T ater occurred 
at longer intervals, they were much less productive. A Faerish 
specimen of this species placed in the same aquarium bred in 
autumn 1903 and in the spring of 1904, the latter being probably 
its normal, and the former an unusual breeding season, induced by 
change in the environment, rise of temperature being probably an 
important factor (though better feeding may have contributed to 
the result).* 
Mr Chaffers states that his specimens of S. troglodytes and 
A. mesembryanthemum, which are 4ed twice a week, bring forth 
young at all times of the year except during the cold weather. 
Daly ell (p. 214) states that “ feeding certainly promotes fertility ” 
in Actinia mesembryanthemum. 
From these facts it appears that temperature and feeding 
exercise a very considerable influence upon the production of 
young in these forms of life. 
Sagartia troglodytes and Actinia mesembryanthemum are 
viviparous ; the former may also be oviparous (see p. 299). 
Bunodactis ( Bunodes ) gemmacea is usually viviparous, hut Mr 
Chaffers has observed, on one occasion, the extrusion of ciliated 
larvae. 
Little is known concerning the rate of growth and the duration 
of life in Coelenterates, hut it may he useful to collect here some 
of the scattered references to these subjects. 
Hydrozoa . — Evidence shows that Hydroids grow rapidly, for, as 
Hincks (1868, p. xliii) remarks, “timber immersed in the sea is 
* This specimen was taken from a pool near high-water mark, where food 
was probably not abundant. We have noticed, on the west coast of Scotland, 
that the largest specimens are almost invariably found in the pools near low- 
water mark, those living in pools higher up the beach being distinctly 
smaller. 
