W. C. Minor upon Fission in some Annelids. 35 
Art. I1V.— Upon Natural and Artificial Section in some Cheelopod 
Annelids ; by W. C. Minor. 
THE circumstances of spontaneous fission have been observed 
in so few species of annelids at present, as to make every additional 
observation of value, even though only confirmatory of what is 
already known upon that subject. This consideration, and the 
fact that all views of its nature in the Oligocheta seem to be based 
upon the observations of one species—Stylaria proboscidea,—have 
tempted me to publish the following brief investigations, how- 
ak they may want of any very special novelty to give them 
value. 
It is now nearly one hundred years since the distinguished 
Danish naturalist, Otto Fr. Miiller, studied the phenomena of 
Spontaneous fission in the fresh water Naids,’ and his able little 
work, Von Wiirmen des sussen und salzigen Wassers, Kopenhagen, 
1771, largely devoted to that subject, shows that he failed only 
where the imperfect means at his command led him astray. 
The multiplication by artificial section had been observed before 
that, both in the Naids and other animals, and had awakened a 
good deal of general interest; but the multiplication by sponta- 
heous fission seems to have been very nearly if not wholly dis- 
regarded at that time. Nor has its occurrence in the fresh water 
worms received, since then, the investigation that it seems to de- 
mand. For with the exception of a discussion by Schultze and 
Leuckart upon some of the particulars, and, the significance of 
this phenomenon in relation to budding, some ten years and 
4 sweeping denial of its occurrence, or at least of its vital and 
systematic nature, by Dr. Williams, about the same time, no 
one, so far as I am aware, has published any extended observa- 
tions upon the fissiparity of the fresh water Naids since the time 
of Miiller.2 And yet the statements of Dr. Williams, in 
to both artificial and spontaneous fission, are such as to suggest 
at once the importance of a reéxamination.of the whole subject; 
while the great interest given to this question by the remarkable 
Speculations of Steenstrup, together with the interesting varie- 
€s of the phenomenon as observed in the marine worms by 
. Trembley had discovered it long before this, as he: b in his 
P. 8. a Vhist. Pun genre de Polypes d'eau douce, 1744 ;-—and Roesel, in his Jnsekten 
belustigungen, describes the united parent and bud; but the former did no more 
‘ae observe the fact, and the latter wholly misunderst 
turgeschi for 18 
Which, so far as there given, I 
