486 Miscellaneous, 



establish the validity of that beautiful law, namely, that all the 

 appendages of the inferior part of the body in the Articulata are esseii- 

 tially analogous to each other ; this being amply demonstrated both 

 by their details of structure, and the various transformations through 

 which one of these appendages passes before arriving from the most 

 simple to the most complex form. — Comptes Rendus, April. 



MICROSCOPICAL STRUCTURE OF SHELLS. 



Dear Sir, — The ' Annales des Sciences Naturelles ' for February 

 last (published, however, but a short time since) contains an abstract 

 of my paper on the Microscopic Structure of Shells, &c. which ap- 

 peared in your Journal for December 1843. Prefixed to this abstract 

 is the following note by the editor, M. Milne-Edwards : — " En re- 

 produisant ici un extrait du memoire de M. Carpenter, je crois devoir 

 reparer une omission que Ton pent reprocher a ce naturaliste, qui ne 

 fait aucune mention des travaux de ses devanciers. En 1786", 

 Herissaut publia dans les ' Memoires de 1' Academic des Sciences,' 

 un travail remarquable sur I'organisation des coquilles, et arriva a 

 des resultats tres voisins de ceux que M. Carpenter tire de ses propres 

 experiences." 



Having every reason to believe that my researches were as novel 

 as they unquestionably were original, I was much surprised at this 

 accusation ; more particularly as many of my results depend upon 

 the improved powers which the microsco23e has recently acquired, 

 and could scarcely have been anticipated, therefore, by any writer of 

 the last century. But my astonishment was still greater, when, on 

 referring to the volume cited by M. Milne-Edwards, I found that no 

 such memoir is to be found in it. Nor have I been able, by con- 

 sulting the index-volumes of the Memoires, to find either the name 

 of M. Herissaut, or any paper on the structure of shell, subsequent 

 to the well-known contributions of M. Reaumui-, which liave formed 

 the basis of all subsequent statements as to the formation and growth 

 of shell. 



I have also spent many hours of valuable time in searching through 

 the various articles on the subject in the several dictionaries of Na- 

 tural History, as well as the systematic works of M. de Blainville, 

 M. Desliayes, and other conchologists ; and the only reference that 

 I can find to the researches of M. Herissaut is confined to the article 

 Conchyliogie in the ' Encyclopedic Methodique,' in which he is quoted 

 as having endeavoured (but failed) to establish by " les experiences 

 ingenieuses, bien plus que solides," that shells grow by intus-suscep- 

 tion, like the bones of Vertebrata, instead of by accretion, as de- 

 monstrated by Reaumur. 



The only instance in which, so far as I am aware, I had been an- 

 ticipated by others, is in regard to the skeletons of the Echinoder- 

 mata ; and I have fully stated this fact in the paper, — not in the least 

 wishing to take credit for what did not belong to me. My researches 

 on this subject, however, had gone far beyond those of Prof. Valen- 

 tin, before the publication of his Monograph. 



I think, therefore, that I have a right to caU upon M. Milne-Ed- 



