236 DENTALIAM;. 



contact with one end of the branchiae. That naturalist cer- 

 tainly connects the two organs by stating, as. I think erro- 

 neously, that the heart sends great and numerous vessels to 

 the branchiae. Now, the heart never transmits blood directly 

 to the branchiae, but impels it into the system by arteries and 

 veins, from whence, as I have already stated, it reverts to 

 those organs. 



The filaments in dispute I have submitted to microscopical 

 observation ; they only present the appearance of a compli- 

 cated mass without a trace of particular arterial and branchial 

 vessels, and they have nothing like the symmetry of branchiae ; 

 I believe them to be merely secreting glands, and they may 

 perhaps combine tentacular functions. 



M. Deshayes is, I think, in error in stating that the aliment 

 undergoes a second mastication : this idea has arisen from his 

 having divided the gizzard into two parts, one of which he 

 describes as " machoires," and the other as an " appareil 

 dentaire assez complique:" the fact is, there are no hard 

 parts in the buccal pouch ; which, when removed, there being 

 no internal oesophagus, exposes to view the anterior part of 

 the gizzard, which is likened to two spherical black points 

 gaping like a small bivalve : these are only part and parcel of a 

 whole the gizzard, which may almost be called the stomach 

 itself, as it fills the entire stomachal membrane, with the 

 exception of the convoluted intestine at its base ; consequently 

 the aliment has no other mastication but of one denticular 

 apparatus. 



That there are no errors in these observations would be an 

 undue assumption; for who, on such subjects and in the 

 examination of these minute objects, can hope to escape from 

 occasional error? I invite malacologists to offer their cor- 

 rections, if I have differed on insufficient grounds from so 

 eminent a naturalist as M. Deshayes ; and I conclude with 

 the evocation, 



Si quid novisti rectius istis, 



Candidus imperti. 



