W. C. Minor upon Fission in some Annelids. 43 
But from the almost uniform success of my own, I should won- 
der that they have done so, had not others reported complete or 
partial failures in similar experiments.—See Dugés, Ann. des Sev. 
1828, Ite Série, T. xv. It must be remembered, however, that 
such evidence is wholly negative, and cannot weigh with the posi: 
tive statements of observers like Miiller, Réaumur and Duges. 
_ In regard to my own observations, [ may state, in brief, that 
In Nylaria, Nuis, and Dero, I have hardly ever failed to have 
the head reproduced, and that the anal end has not on 
Teprocduced in these genera, but I have seen it reproduced in En- 
chylreus, in Lumbricus, in Fabricia, and even in a Nereis common 
on our coast.1' That in the vast majority of these cases I have 
seen fuod taken again; and, in all, I have seen the incurrent anal 
Stream, which ceases while either end is closed, recommence. 
From these and other observations, I am inclined to believe that 
this power is far more general in the class than is yet supposed, 
That this power plays a part in the natural economy of life, 
the healing fragments of Naids that I have found in our pools 
$a proof. When saved from the attacks of Chetogaster, even 
the shortest, headless, and almost immovable, fragments may 
p on to as full a recovery as when preserved by the observer. 
One instance, I found, Aug. 2Lst, what was apparently five seg- 
ments of some Nuaid’s trunk, the two ends of which had closed 
and elongated. This had been preserved for some time, for the 
& fapid growth, developed eyes about the 22nd, opened the 
newly formed mouth about the 23rd, was supplied with food, 
5-16 
then gave off 5 buds in succession at that point till Oct. 8th, 
When it was lost. . . 
The thin film with which the Naids line the jars in which they 
re Kept may be seen to serve, there at least, as a protection 
against the attacks of the prowling carnivorous Cheetogasters, and 
Once beneath this, a fragment, like the one just referred to, may 
Preserved till the eyes and mouth are formed—a period usu- 
ally of a fortnight. And though we should hardly have expected 
* llere piece of five segments to be preserved as this was, even 
though endowed with the power of recovery, yet we cannot re- 
ee 80 extended and remarkable a function as this appears to 
~~? 88 useless or inoperative in the natural course of Naid-life. 
a Careless observations niade a number of years ago led me to think that the 
fae ee 4 destitute of the power of recovery from. geen = Rew a 
thors. y 5 Ways sloughed away ring alter ring, in his experiments. umur re- 
ani i] tatate - i Bae 
“S? Mais les essais n'ont peutétre pas éte encore assez répétés ni assez suivis,”— 
eet a 8.2 Thist, pay jaorm a Np. 69 Thinking the latter statement iy 4 
: es ipees the experiments during the past year, with more care, and 
success, 
