144 Colonial Organisms. [ February, 
Volvocinez, as we shall show farther on. It will suffice to say 
here that these colonies are the product of continued asexual 
reproduction, and of the coherence of individuals thus pro- 
uced. 
Of colonies of Metazoa those of the sponges are similarly the 
result of asexual reproduction, are unattended by specialization | 
of any members of the colony, and their members may be sep 
rated and pursue individual lives, and produce new colonies. The 
sexually generated sponge, on the contrary, begins life as a free 
individual. | 
But the subject of the sponge leads us deeper into the question 
of reproduction. As is well known there are two hypotheses & 
tant in regard to the classification of the individual sponge. In 
the one it is viewed as a colony of Flagellate Protozoa. In the 
other it is viewed as a single Metazoan. The former hypothes 
is based on the cellular organization of the sponge, since mosto 
the cells of its epidermal layer are essentially Flagellate Infi- | 
soria. The latter is based on the character of its reproductioh 
since the germ develops in Metazoan fashion and not by a pre 
cess of colonization. ` : 
It has been assumed that these hypotheses are mutually excl 
sive, and that only one of them can be true. Yet this does 1 
necessarily follow. They may both be true. The strong ee . 
ment which each advances may perhaps be reconciled by ¢ oo 
hypothesis, or by a fuller consideration of the essential chara eR d 
of reproduction. | 
The assumption that a compound organism which is born a5? 
single cell, and grows by asexual budding, is a Protozoan pone q 
and that one which is born as a definite compound of p gs 4 
Metazoan individual, has its uses for purposes of classi 1 
but it declares a distinction that has no real existence. * | a 
consider birth in its true relations, all organisms are born a> he i 
gle cells, and their complete development takes place after gë 
For birth really occurs at the moment in which the germinal a : 
ceases to be a part of the parent organism, and begins its indi o 
ual life. Whether it is delivered directly into the suiro  / 
elements, or into an ovary within the maternal body, the Se 
tial fact remains the same. It has ceased to be a constituent P | 
of the maternal body. It occupies an external locality, we 
the exterior world or in a cavity communicating therewith" 
