4 BRITISH TUXICATA. 



when a few species were noticed by several naturalists 

 who confused the subject by placing them with the 

 Alrijumn-id. It was not until the 12th edition of the 

 ' Systema Naturae' of Linnaeus appeared [i, 2 (1767)] 

 that the simple forms were drawn together under the 

 generic appellation of Ascidia, the name Tetlujs being 

 restricted by Linnaeus to the animal of the Bivalves. 

 The union of Trtlujum with the AsciJiirm, of Baster 

 [' Opusc. Subsec.,' i (1760)] had already been suggested 

 by Pallas [' Miscel. Zool.' (1766)], 'and both these 

 naturalists observed the resemblance of these animals 

 to the bivalve Mollusca, as indeed did Linnaeus. 



Cuvier's first observations on the Tunicata were 

 made in 1797 [in ' Bull. Soc. Philom.']. Then followed, 

 in 1815 [in 'Mem. du Mus.,' ii ; see also 'Mem. des 

 Moll.' (1817)], his anatomical researches, which gave 

 a solid, sound foundation as a starting-point for 

 succeeding investigators. This profound anatomist, 

 whose observations were extended to the compound 

 forms, determined the high differentiation of the 

 organism, and proved the close relationship existing 

 between the Tunicata and the Mollusca. But it is 

 erroneous to assert, as some have done, that these 

 justly-celebrated investigations had been carried as 

 far as it was possible to carry them with specimens of 

 Tunicata preserved in spirit. All the organs can be 

 fully determined in simple Ascidians so preserved, not 

 excepting the heart and the vascular apparatus even 

 to its minutest ramifications. AYhat Cuvier did he 

 did well, and he achieved all that was demanded of 

 him by the requirements of science at that time. 



Cuvier was also the first to recognise the affinity of 

 the simple and compound Ascidians, but Pallas seems 

 to have suggested this in the few preliminary remarks 

 to his description of the Botryllus steUntns of Graertner 

 [' Spic. Zool.,' fasc. x (1774)]. Cuvier advanced this 

 opinion in the report on Savigny's celebrated 

 " Memoires ' \_Sur les Asd^ics rni)i]_>o*<'<'S cf les A$rirUt->x 

 simples] read on the 8th of May folio wing the date of their 



