LIFE OF ALBANY HANCOCK, BY DR. EHBLETON. 



125 



M. de Quatrefages had stated that Eolidina possessed a heart 

 and arteries, but no veins; that, therefore, the circulating ap- 

 paratus was incomplete, the blood flowing to the heart through 

 a series of open spaces in the areolar tissue of the body ; that 

 the mouth had no teeth ; that the alimentary canal passing down 

 the median line of the body ended in a dorsal anus, whilst there 

 were given off on each side a symmetrical series of branches, 

 equalling in number the dorsal papillae, to each of which an off- 

 set was given, after which the branches ended in a narrow mar- 

 ginal canal running all round the body. 



M. Milne Edwards had (in 1842) declared the existence of a 

 similar apparatus in Calliopcea, and had named it "a gastro- 

 vascular system," believing that the digestive system, by its 

 complexity, replaced in that animal the venous parts of the cir- 

 culating system, and also the organs of respiration. 



On dissecting in 1844 an Eolis, or Eolidina, taken at Culler- 

 coats, we found that veins, as well as arteries, were present ; that 

 the mouth contained a spiny tongue ; that the alimentary canal 

 ended on the right side of the body, and that there was no mar- 

 ginal canal with which the branches from the stomach could 

 communicate ; that the branchial papillae were the respiratory 

 organs; that, therefore, the functions of digestion, circulation, 

 and respiration, far from being performed by one system only 

 (a gastro-vascular), had each its own special organ. 



M. de Quatrefages, in 1844, communicated to the Annales des 

 Sciences Naturelles, t. 1, p. 129, another memoir, in which he 

 attempted, on the strength of his own previous observations and 

 those of Milne Edwards, to establish a new order of Mollusks, to 

 be called Gasteropoda Phlehenterata. In this memoir he stated 

 that six genera of Mollusks possess a gastro-vascular system, and 

 that, in fact, the three great functions of life — circulation, respi- 

 ration, and digestion, are performed in them by one system only 

 of organs, thus degrading these Mollusks to the level of the 

 Acephalous Medusae ; and he, moreover, endeavoured to lay down 

 the vicious principle that the external characters of animals are 

 altogether independent of, and are no key whatever to, their in- 

 ternal structure. 



