1895.] Notes on the Reproduction of Plumularian Hydroids. 969 
nies having independent hydrorhize ; neither is it equivalent 
to the multiplication often effected by mutilation. There is 
no mutilation in this case, unless we may so regard the spon- 
taneous atrophy of the connection between the old and new 
colonies. 
That this stoloniferous multiplication is normal is indicated 
by the fact that specimens fresh from the sea exhibited the 
greatly elongated and forked hydrocladia. 
_ It may be well to note that P. pinnata seems to have repro- 
ductive powers greater than those of any other Plumularian 
known to me. At the proper season that part of the stem from 
which the hydrocladia spring is fairly packed with gonangia 
which may even be crowded out onto the hydrocladia. In 
some instances it seemed as if the reproductive potentiality 
demanded some other outlet, and long processes, exactly like 
the hydrocladial processes described above, were seen spring- 
ing from the interior of the gonangia themselves. 
The possibility of conjugation among the Plumularidae. 
During the months of June, July and August a small spe- 
cies of Aglaophenia was brought almost daily to the Naples 
Zoological Station. It grows on a long ribbon-like alga in 
shallow water and bears a general resemblance to A. pluma 
Linn., from which it differs in exhibiting a frequent intercala- 
tion of intervening internodes on the distal half of the stem, in 
the more distant hydrocladia, and in having, as a rule, not 
more than three hydrothece to each internode. 
In June it was noticed that a large proportion of the colo- 
nies had the end of the main stem greatly elongated and en- 
larged, the proximal part of this extension being divided into 
a great number of short internodes, while the distal portion 
was abruptly bent over so as to form a nearly closed hook. In 
many cases the ends of two colonies would be hooked together, 
clasping each other so tightly that they could not be separated 
without mutilating the specimens. This state of affairs was 
so common at this time that one could not regard the attach- 
ment as accidental or abnormal, and further developments 
were awaited with great interest. 
