ELISHA MITCHELL SCIENTIFIC SOCIETY 84 
piece cut out would not seriously injure the sponge, and 
would show the quality of fiber as well as the entire 
body. ‘Selected individuals might be removed from the 
general ground and during the breeding season placed 
together in large live boxes. The ‘‘spat’’ collected from 
such individuals would doubtless develop into superior 
sponges. I do not know any marine animals which would 
seem to be so adapted to continuous rearing, with'constant 
improvement of breed,as sponges. Their plant-like habit 
of growth make it easy ‘o handle and experiment upon 
them. Their variability, especially in the matter of the 
skeleton. would seem toinsure success to selective breed- 
ing;and the very simplicity of what is desired, namely, 
improvement in the quality of the skeletal fiber, would 
at once lenda directness to the cultivator, which should 
lead to comparatively early results. 
In closing, I may direct your attention to a methed of 
race improvement, so far practiced only in the cultiva- 
tion of plants, but to which the vegetative character of 
“sponges will readily lend itself. I refer to the method of 
oratting. The case: with which two or more individuals of 
the same species of sponge, irrespective of age, may be 
made to fuse, and become henceforth a single individual, 
is well known. Dr. Grant records observations on this 
head as far back as 1826. Among later experimenters I 
will only mention Vosmaer. This fusion of individuals 
goes on commonly in nature. An interesting account of 
a number of cases may be read in Johnston’s British 
Sponges and Corallines, published 1842, page 11. 
The natural tendency of sponges to grow together, 
coupled with the ease with which they may be propagated 
by cuttings, wouldimake artificial.erafting in these animals 
a simple matter. With asmall plantation of very super- 
ior sponges at hand, the result of careful breeding from 
selected individuals, and other plantations consisting fo 
