MR. HUXLEY ON THE ANATOMY OF SALPA AND PYROSOMA. 
591 
73 . The ‘‘Ciliated Sac" and “ Languet" — Cuvier refers to this organ in Salpa 
Tilesii as “ I’anneau irreguli^re qui la termine (la branchie) en arriere.” 
It has already been mentioned that this organ is mentioned by Chamisso as a 
problematical nervous apparatus. Quov and Gaimard described its thickened rib as 
a vessel, adding, “ nous dirons un vaisseau parceque nous croyons avoir vu le sang 
circuler dans son interieur,” apparently mistaking the ciliary motion for a circula- 
tion. 
Meyen calls it the “ Respirations-ring,” and says that it is a respiratory organ. 
He first described the cilia, but denies the existence of any aperture leading into the 
organ. 
In S. mucronata, not perceiving that he has to do with the very same organ 
under a different form, he describes the “ ciliated sac ” as a testis. The ianguet he 
calls simply “ Haken.” 
Eschricht gives it and the Ianguet together, the name of das langliche organ,” 
and considers it as a tactile organ analogous to the pulps of bivalves. He rightly 
describes the nervous cords connecting it with the ganglion. 
Sars confirms Eschricht’s view, and considers the organ as analogous to the ten- 
tacles of the Ascidians, which, however, cannot be the case, as in many Ascidians 
(e. g. Clavelina) the tentacles and the “ languets” co-exist*. 
M. Milne-Edwards figures the “ciliated fossa” as the “ fossette prebranchiale ” 
in the plates of the last (commemorative) edition of Cuvier’s Regne Animal.’ 
74 . The Structure of the Heart. — Eschricht and Sars describe Ihe heart to be 
composed of a series of vesicles, which is certainly a mistake, arising from the fact 
that the heart always presents two or three constrictions, so as to appear almost 
moniliform. 
75. Tubular System. — This is figured by MM. Quoy and Gaimard (pi. 88, fig. 12) 
in Salpa pinnata, under the name of “vaisseaux mesenteriques.” Is it to this struc- 
ture to which M. Krohn refers, when he says that “ the meshes or lamellae of the 
elseoblast are traversed by numerous vessels opening into two trunks, which appa- 
rently form the attachment between this organ and the visceral nucleus?” 
Perhaps also it is to this system that Eschricht refers when he speaks of the in- 
testine as beset with “ stalked granules.” 
76. The Gemmiferous Tube. — Cuvier, Savigny, Chamisso and Quoy and Gaimard 
consider this structure as more or less partaking of the nature of an ovary. 
Meyen mistakes it for a liver in Salpa democratica. Eschricht describes the pro- 
cess of development of the young from the gemmiferous tube and their connection 
with it very carefully; but he does not seem to consider it as mere gemmation. 
He calls the organ “ Keim-rohre,” germ-tube, and considers it as a “ quite new 
form” of propagative organ. From the mode of expression in the following para- 
* In the Cynthia examined by the author (see note (65.), the “ ciliated sac” was seated upon a tubercle^ 
but there was no “ Ianguet.” 
4 G 2 
