AMPHITRITE. 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 branchiae 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 

 vcntilabrum, 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 XXXII., 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 



'2n 



