172 THE AMERICAN. NATURALIST. 
products, an epitokal form like that in Eusyllis, Odontosyllis, 
and Exogone, and stolonization as a secondary condition ac- 
quired for the purpose of a more perfect distribution of the 
sexual products. The complete epitokal changes in Autoly- 
tus have already been observed by Malaquin in Autolytus lorge- 
feriens, and described by him under the name of “ epigamie,” 
and it is very probable that a further study of the different 
species of Autolytus found along our coast would yield similar 
results. From our present knowledge it would appear that, as 
in Autolytus cornutus, the epitokal changes have been lost, or 
at least in greater or lesser part suppressed, in the parent stock 
of some syllids, and that in this way closely related forms of 
syllidians may exhibit sexual changes as various or more so than 
are shown in different species of Nereis ; but it is very doubtful 
whether in any of our species the loss of sexual products has 
been so equally shared with these other changes as to leave a 
distinctly asexual parent stock. 
The high development of the head of the stolon would form 
the strongest argument in favor of the distinct individuality of 
the stolon. Malaquin (Recherches sur les Syllidiens) has, how- 
ever, already shown that the head of the stolon in different 
species of syllidians presents very different grades of develop- 
ment. In making this comparison he says: ** L'individualisa- 
tion du stolon diminue de plus en plus, au fur et à mesure qu'on 
suit la marche graduelle de ce phénoméne. autrement 
dit la téte qui marque pour ainsi dire le degré de perfectionne- 
ment de son individualité, se simplifie de plus en plus et arrive 
méme à ne plus se former du tout." His figures, in which he 
compares the head of the stolon of Haplosyllis hamata, in the 
formation of which no development of a head takes place, with 
that of Trypanosyllis, in which a small head supplied with eyes 
is present, and, by different intermediate forms, with the com- 
plicated head structures of Autolytus, very clearly indicates, as 
had already been suggested by Huxley, that the stolon among 
syllids is not as distinctly individualized as would appear in 
observations on Autolytus by itself. 
URSINUS COLLEGE, COLLEGEVILLE, PA., 
900 
