612 BULLETIN OF THE BUREAU OF FISHERIES. 
individuals of Tethya lyncurium, ultimate disappointment may be frequently 
met, arising after premature cicatrizations. 
Buccich questioned, on the other hand, whether no senile degeneration took 
place on cuttings obtained from senile sponges; the growth of these would be 
slower than that of asponge of the same dimensions but developed spontane- 
ously. This last proposition was entirely confirmed by facts, as we have already 
seen; but it should not be deduced thence that the opinion of Bidder on the 
senility of sponges has been verified. It is impossible to compare experiments 
made on intact sponges with cuttings attached to apparatus. Let us observe, 
however, as an accessory consideration, that Allemand thinks to have observed 
that cuttings taken from large sponges do not develop as well as those from 
small-sized sponges; but his information on this subject is quite meager. As 
far as the senility of sponges is concerned, our knowledge, I believe, is limited 
as yet to some measurements which Allemand made at Sfax. He noticed that 
in some fifteen months the circumference of certain sponges increased from 40 
to 45 centimeters and of others from 50 to 54 centimeters, while some increased 
from 60 to 63 centimeters, which means an increase in volume of 455 cubic cen- 
timeters in the first case, of 544 in the second, and 580 in the third. It can not 
be said that these observations constitute a definite demonstration of the fact 
that the sponges had their vitality weakened as they advanced in age. 
These are questions, moreover, the importance of which is purely theo- 
retical, since sponge culture by cuttings can not be the subject of practical 
application. The methodical study which I have given here leads us inevitably 
to the conclusion which sponge culturists themselves were obliged to accept. 
Wesee that Monroe says doubtfully: ‘‘It is quite possiblethat * * * sponge 
culture might be profitable;’”’ yet, after all, he thinks that the most rational 
method is sponge culture by means of collectors. The last experimenter who 
took up this question could not answer against the argument arising from these 
observations. After having said that sponge culture by cuttings possesses real 
industrial value, which I expressly deny, he ends, nevertheless, by preferring to 
it a mixed method in which, unfortunately, he has no personal experience. He 
considers as being ‘“‘the true method of culture in the future” a combination 
of sponge culture by cuttings and sponge culture by planting; the cuttings 
would produce larve which would stock the pare. There would thus be every 
four or five years a harvest from the cuttings which had grown and every two 
years another from the sponges spawned in the pare. This mode of operating 
does not seem at all justified. It is difficult to understand why the author 
does not advise sponge culture by means of collectors as previously studied; 
why he insists upon utilizing, in spite of everything, the method proposed by 
Schmidt. Since the cuttings require five years to reach the size which the 
sponges reach normally in two years, it is very probable that the emission of 
