994, W. WOODLAND. 
figures two nuclei as the maximum number attained in the 
formation of the comparatively simple spicules of Clavularia 
prolifera. Why only two nuclei are concerned in the for- 
mation of these Alcyonarian spicules I cannot at present say, 
and I have therefore no & priori objection to the existence of 
multinucleated spicules, and am quite ready to accept pro- 
visionally, e. g. Bourne’s other statement that, so far as he has 
been able to ascertain, the ‘‘scale-like spicules in Primnoa 
and Plumarella are formed by several cells, or at least by a 
comparatively large ccenocytial investment containing many 
nuclei;” all I at present contend is that, strange as the fact 
may appear, the huge spicules of Aleyonium digitatum 
never, in the ordinary course of things, possess more than 
two nuclei embedded in the wall of the protoplasmic sac 
which envelops them. 
Starting from the “caudal vertebra” stage, different spicules 
develop in different directions assuming unlike forms. Nearly, 
if not all, the different forms are derived from the ‘‘ caudal 
vertebra” condition by the special development either (1) of 
the large processes (see text-fig. C below) derived, as just 
described, from the rims of the amphiccelous extremities 
(some of the minor processes occasionally replace these, how- 
ever, as the figures show), i.e. of some or all of the four 
angles or corners of the spicule basis when this is viewed 
from a lateral aspect, or (2) of one or both of its two ends, or 
(3) of the two sets of processes combined. In fig. 8,e. g. two 
of the diagonally opposite angles have become specially 
developed, and similarly in fig. 9, though here, owing to the 
spicule lying edge-on, the two processes resemble the elon- 
gated ends of the spicule and not its corners; in fig. 10 two 
of the angles on the same side of the spicule, but not in the 
same plane; in fig. 11 two of the angles at the same end of 
the spicule and the opposite extremity, and similarly in fig. 
12; in fig. 13 three of the four angles; in fig. 14 all of the 
four angles, two more so than the opposite pair. It will be 
seen from the figures that in the growth of these angles or 
ends, the actual prolongation may not, as before pointed out, 
