POPULAR SCIENCE REVIEW. 
38 
is the same that has produced the P or pita, or the Vele.Ua, — the 
formation of the colony, or association, the physiological division of 
labour , the manifestation of polymorphism, and finally, the con- 
centration of the parts thus elaborated. Such, from the morpho- 
logical point of view, is the succession of the phenomena which 
mark the transformation of the Hydroid Polypes into Velellce 
and Sea-anemones. The Hydroid Polypes are the raw materials 
which are brought into the factory, and then fashioned and 
definitely assembled to form these superior individualities. 
Whilst these phenomena are occurring in the morphological 
sense, others are manifested in the physiological. The asso- 
ciated indivi duals have at first nothing in common, unless it he the 
nutrition, which all are capable of elaborating, but which passes 
from one to the other in such a manner that all the members 
of a colony may equally partake of it ; this is in reality the 
commencement of solidarity, but each polype, nevertheless, 
possesses its own personality. It has its personal will, and 
does not communicate to its neighbours the sensations it expe- 
riences ; we may wound, or even remove it altogether, without 
any consciousness on the part of its neighbours. But in pro- 
portion as the colony becomes more coherent, the sensations 
radiate further and further around the polype ; very soon all 
the individuals are sensible of actions performed upon any one 
of them ; a colonial consciousness is thus manifested over and 
above the individual consciousness ; and, finally, a single will 
bends all the special wills to its bidding. At this moment a 
new individual is definitively constituted. 
The transformations that we have been able to trace, step by 
step, in the class of Polypes, are not peculiar to those animals. 
It would be just as easy to show how simple forms have in the 
same way become associated in the great group of the V ermes, 
to lead up to complicated forms ; it would be just as easy to 
recognize in this interesting group the laws to which the study 
of the Polypes has led us. It is already a long time since 
Professor Van Beneden asserted that each joint of a Tape- 
worm was the equivalent of a Trematode worm, a Fluke ; and 
for a still longer period the segments of a worm, or of an 
insect, have been regarded by naturalists as perfectly equivalent 
units, all formed of the same parts, and each having an actual 
individuality. The name of zoonites, which has been applied to 
them, would even seem to indicate a tendency to regard them 
as actual elementary animals, which had formed colonies by 
their association. The faculty possessed, in certain worms, by 
each of these segments of individualizing itself, and forming 
a new colony, bears high testimony to the correctness of this 
view ; polymorphism and the concentration of parts suffice to 
explain how a Peripatus or a Myriopod may have become trans- 
