ANATOMY AND PHYSIOLOGY OF SALPA AND PYROSOMA 65 



a detailed historical account of all that has been written upon the 

 SalpcB, it may be of interest to notice, with a view to reconcile, a few 

 of the more important discrepancies among the statements of the 

 chief investigators. And first : 



Of the sides and ends of the Salpce. — On so simple a matter as this, 

 almost every writer has different views. Cuvier calls the ganglionic 

 surface ventral, the opposite dorsal, the nuclear end anterior, the 

 opposite posterior. Savigny appears to follow him. Chamisso follows 

 Cuvier as to the anterior and posterior ends, but reverses the dorsal 

 and ventral sides. 



MM. Quoy and Gaimard give the ganglionic end as anterior, the 

 nuclear as posterior, the nuclear side as ventral, the ganglionic as 

 dorsal 



Meyen gives the same determination. Eschricht considers the 

 nuclear end to be posterior, the ganglion side ventral ; as also Sars. 



M. Milne-Edwards seems to follow Chamisso. It is much to be 

 wished that some uniform nomenclature could be adopted. The 

 reasons for the terms used in the present paper have already been 

 given (5). 



72. The Nervous System. — The nervous system was denied by 

 Cuvier altogether. Savigny describes the ganglion, without recog- 

 nizing its true nature, as the " tubercule qui dans les Ascidies est 

 contigu au gros ganglion.'' 



Chamisso describes what appears to be the thickened edge of the 

 " ciliated fossa," and states that Eschscholtz considered it to be a 

 nerve {pp. cit. 'p. 5). 



Quoy and Gaimard describe the ganglion, but omit all mention of 

 the auditory sac. 



Meyen claims the discovery of , the true nervous system ; but 

 although he figures it pretty accurately, he omits all mention of 

 the otolithic sac, and seems after all in doubt whether it may not 

 be a respiratory organ ; and it was reserved for M. Milne-Edwards to 

 give the first satisfactory account of these structures. 



Both Eschricht and Sars subsequently omit to describe the audi- 

 tory sac. 



73. The " Ciliated Sac " and'' Languet." — Cuvier refers to this organ 

 in Salpa Tilesii as " I'anneau irreguliere qui la termine (la branchie) 

 en arriere.'' 



It has already been mentioned that this organ is mentioned b/ 



Chamisso as a problematical nervous apparatus. Quoy and 



Gaimard described its thickened rib as a vessel, adding, "nous 



dirons un vaisseau parceque nous croyons avoir vu le sang cir- 



VOL. I -r. 



