182 Miscellaneous. 
posterior arthrobranch of segment 12, was forked. The bifurcation 
began close above the base, the two branches being nearly equal to 
one another in size and haying the usual structure. 
Specimen I1I.—This specimen presented a partial fusion of the 
fourth and fifth abdominal segments. Looked at from the tergal 
side the abnormality could not be seen, but the calcified sternal bars 
were completely fused from the middle line nearly to the attach- 
ment of the appendage on the right side. On the left of the middle 
line the two sternal bars were separated by a narrow uncalcified 
portion, and a certain amount of movement between the two seg- 
ments was still possible, owing to the elasticity of the narrow and 
partially fused sternal bars. The appendages were normal, but the 
distance between the attachments of those on segments + and 5, left 
and right, was naturally much less than usual, as the sternal region 
of these segments was so much reduced in length. 
Cardiff, 
Jan. 12, 1892. 
The Chromatophores of Cephalopods. 
By M. Rapwakn Birancuarp. 
The radiating fibres which are found around the chromatophores 
of Cephalopods have been described by various authors as muscles 
which are inserted into the enveloping membrane: by contracting 
they would expand the chromatophore, on relaxing they would 
permit it to revert to its original condition and to efface itself more 
or less. 
In the year 1882 I showed that, during the changes of form to 
which they are continually subject, the chromatophores alone are 
active. As a matter of fact attentive histological study enables me 
to state that the radiating fibres are neither muscles nor nerves, but 
simply fibres of connective tissue, presenting a peculiar orientation 
in the neighbourhood of the chromatophore, with which, however, 
they have no connexion. Soon afterwards a perfectly similar state- 
ment was made by M. Girod; this very year these observations 
have received further confirmation at the hands of M. Joubin *. 
Nevertheless it has been recently stated by M. Phisalix fT that 
“ the radial fibres are muscles,” and he affirms that the expansive 
movements of the chromatophore “ are determined by the contrac- 
tion of muscles arranged radially at its equator.” He mentions 
elsewhere the writings of M. Girod, M. Joubin, and myself. 
M. Phisalix cites, in support of his opinion, the researches of 
MM. Paul Bert and Frédéricq ; but neither of them has verified 
anatomically the muscular nature of the radiating fibres; if they 
attribute this structure to them, it is solely because it was admitted 
by the naturalists of the period. The interesting experiments made 
by M. Phisalix, following upon those of the two observers mentioned 
above, are explained by the intimate union of the chromatophore 
with the nerves. J expressly recoynized this union, and the result 
of my observations appears to me to remain unimpaired.—Comptes 
Rendus, tome-exiii. no. 17 (Oct. 26, 1891), pp. 565, 566. 
* Ann, & Mag. Nat. Hist. 189], viii. p. 111. t+ Vide infra. 
