Vol. VIII, No. 2.] The Freshwater Fauna of India. 49 
[N.S.] 
of the water: the individual must perish but the race may be 
preserved. At this season Hydra, which has been reproducing 
its kind by means of buds throughout the summer, develops 

and the sponges gemmules. Statoblasts, hibernacula, 
gemmules are alike produced asexually, but they resemble the 
eggs of Hydra in being provided with a hard, resistant shell, 
and in having the capacity to lie dormant until favourable con- 
ditions return.”’ 
The preceding passage is quoted from the introduction to 
my volume in the ‘‘ Fauna of British India’’ on the Sponges, 
Polyzoa and Hydrozoa. I should perhaps explain that the 
bodies alluded to as gemmules, statoblasts and resting buds 
are all structures produced by the aggregation of cells richly 
laden with food material and the secretion round them o 
horny coverings often of a highly complex nature. Hiberna- 
cula are apparently fixed in all cases to some solid object, and 
this is the case also with some or all of the gemmules or 
directly to the desiccation of ponds and lakes. We now know 
that it is not always so. A large proportion of the lower 
