558 BULLETIN OF THE BUREAU OF FISHERIES. 
(pl. Lx1x) or of approximately the same volume, were the best, all things con- 
sidered. The shape of the cuttings will, of course, vary with the size and shape 
of the seed sponge, but the more nearly equilateral they can be made, the more 
generally satisfactory they will prove. Thin edges or ragged parts are likely to 
die and slough off. 
In making the cuttings it is generally better first to cut away the roots of 
the seed sponges if they contain fragments of rock or coral or shells. Otherwise 
much time is lost through the dulling of the knives. For this rough work it is 
well to use a heavy knife with its edge serrated by vertically grooving the flat 
face of the blade with a three-cornered file, converting it into practically a 
sharp-edged saw. For making the actual cuttings large butcher knives of good 
quality should be employed, and they should be kept sharp by frequent whetting 
with a coarse stone, such as is used for sharpening scythes. A rather rough 
ragged edge is preferable to a smooth one. If the knife be in proper condition 
the sponges will cut as readily as beef liver, but if it be dull the operation is 
slower and the cuttings are liable to injury by the compression of their tissues 
under the knife. 
The direction of the cuts will depend upon the size and shape of the seed 
sponge, but in the majority of cases the latter should be placed on a wet board, 
root down, and cut into slices from 114 to 134 inches thick, each of these being 
subdivided to best advantage as dictated by the judgment of the operator. 
It is desirable, but not essential, to leave on each cutting one surface covered by 
the uninjured skin of the original sponge. I have successfully grown cuttings 
taken from the interior of the sponge, but while the mortality is no higher and a 
new skin is soon formed over the entire surface, growth appears to be somewhat 
more slowly initiated than in the case of normal cuttings. 
Neither the seed sponge nor the cuttings are injured by moderate exposure 
to the air, but it is safer, especially in hot weather, to throw the pieces into a 
tub of fresh sea water as soon as cut. Care should be exercised to change the 
water at intervals of about one hour, as the cuttings will be injured and probably 
die if left for any length of time in foul water and a few fragments of dead 
sponge will speedily contaminate a tubful. Neither the entire sponge nor the 
cuttings should ever be brought into water much below oceanic saltness and 
care should always be taken to protect the tubs from rainfall, which appears to 
have an effect disastrously out of proportion to its volume. If it is necessary to 
keep cuttings over night they should be placed in netting bags and hung in the 
open water, but they should never be so left more than a day or two, as they 
will soon grow together and be separable without injury only by the knife. Speci- 
mens left in contact for three or four days have grown into conglomerate masses 
difficult to handle. 
