38 W. C. Minor upon Fission in some Annelids. 
conclude that each bud is formed one joint anterior to its prede- 
cessor, that there is thus a gradual reduction of the parent seg: 
ments till a certain point; that then a reformation of rin 
takes place, and an elongation of ti body of the Naid to re- 
commence this circle of fission. 
Schultze, in his article, Uber die Fortpflanzung durch Theilung 
bet Nais wth roboscidea (Archiv Sf. Natur elapse 1849, T’. xv, p 
293,) confirms the statements of Miiller as to the passage over 
of one oF the parental segments to each id ;° though he is not 
fortunate enough to observe the recom mencement of fission in 
the elongated Naid. He observes also (p. 801) that, contrary to 
what Steenstrup had supposed from the analogy of marine 
worms, there is no relation to metagenesis in the phenomena of 
budding i in this Naid, for he had never seen generative organs 
in the separated buds. He had however never been able to keep 
these buds longalive. He also had seen (p. 804,) sexual organs 
in the parent while budding, though he had never seen well de- 
veloped sperm and ripe eggs present during this process. 
The phenomena of fission in Sh ylaria longiseta, so far as I have 
observed them, confirm the statements of Miiller and Schultze 
in substance ; for there is nearly always a passage over of one 
parental ring to each bud, and since fission takes place, as I have 
soi while the parent has eggs and sperm, and I have never 
en the fullest development of the latter i in the buds, I canis ot 
believs that there is any such metagenetic relation in this pro- 
cess as has been observed in Syllis and allied genera. 
In Nais rivulosa, however, the facts are somewhat different. 
For in several continued observations of individual Naids, ex- 
tending in one case over twelve wee ce 
or twice of a passage of the warcenads rings into the bud; while, 
after an elongation of the parent body, ‘I have very uniformly 
seen fission recommence in the point at which buds were given 
off before, or at some point posterior to it, and once anterior, — 
and finally, although I have seen fission taking place between 
each of the rings from the 15th to the 22d, I have not been able 
to discover that it does so in any order. But nt as in Stylaria 
longiseta, I have found no metagenesis in the 
The facts obtained in regard to fission in Daw ee are un- 
ey meagre; the “comparative a of the meris- 
carryin off of parents segments by the spt parts, nor 
_ § Leuckart at first igs the correctness of this view, (Uber die ungeschlecht- 
liche Vermehrung bei Nais proboscidea, Wiegm. Arch. 1857,) but has since beea 
convinced of its justice. 
