AM PHITRITE. 241 
separated below, on November 18, during an attempt to dislodge a speci- 
men from the sheath. Both wounds healed speedily. But nothing had 
been generated from the fragment in fifteen or sixteen days, though it 
formed itself a sheath with an orifice—Plate XXXII, fig. 3. Ninety- 
two days after mutilation, a renovating plume, of greenish colour, con- 
sisted of a short compressed assemblage of ribs, becoming very distinct in 
another week. Several were now acquiring a fringe, and the whole 
reproduction extended about two lines. In 116 days after mutilation, 
the plume almost equalling half the length of the body, unfolded in 
nearly the natural figure. All the parts, old and new, were vivid. Be- 
sides some ribs advancing, eight branchiz were fringed, but the cilia had 
not reached the summit of the rib.—Plate XXXI. fig. 4, regenerated 
branchia ; fig. 5, enlarged. 
While the sundered fragment gained a plume, that of the original 
entire animal still subsisted ; therefore, as exemplified in the Amphitrite 
ventilabrum, here were two cotemporary plumes, two complete systems of 
the branchial apparatus, in vigorous existence at once, on two portions 
which had constituted an integral animal. 
Farther illustration of the subject might be considered superfluous, 
were it not from the interest attending the discovery of similar results by 
artificial mutilation. 
In natural mutilation, succeeded by perfect reproduction, some may 
conclude that there are definite limits, comprehending the elements of 
all the defective parts, whose evolution follows. The same cannot be 
conjectured of artificial mutilation, for there are no external indications 
of such limits, if they do exist, nor of the elements of such parts, to be 
developed subsequently. 
The specimen, Plate XXXIL, fig. 7, was mutilated of half an inch 
of the posterior extremity.—Plate XXXII, fig. 5. 
A specimen having been preserved during six weeks or two months, 
was then dislodged, and half an inch sundered from the lower extre- 
mity ; next day, the anterior portion had ascended the side-of the 
vessel, displaying its plume as if unhurt. In four days it had formed 
itself a slight sheath, and the wound appeared healed. Some very short 
2H 
