Scraps in Natural History. 93 



Art. IX. — Scraps in Natural History, {Molluscs ;) by Dr. John 



T. Plummer. 



The limited area to which I have confined my conchological 

 observations, and the want of suitable opportunities for prosecut- 

 ing my inquiries into the habits of such molluscs as are found 

 within it, have kept my physiological notes on this subject very 

 meagre. I will insert them here, however, for the purpose of 

 preserving the integrity of my plan of accompanying the cata- 

 logues prepared for this Journal with some remarks upon the 

 habits and physiology of the respective classes of animals enu- 

 merated ; and because, if they are not altogether novel, they 

 may prompt others to more extended research into the modes of 

 livir)g of the molluscan race. 



Snails. — I confined several species together in a box filled with 

 vegetable mould ; and in a few hours afterward I found some of 

 them had descended several inches into it, while others were 

 just opening a passage for the admission of their shells, which 

 they also soon dragged beneath the surface entirely out of view. 

 One, a Helix solitaria, had its lip broken off, and made no at- 

 tempt to burrow, but commenced repairing its loss of shell shortly 

 after it was deposited in the box. The process appeared to con- 

 sist in bringing a border of the mantle armed with a row of pa- 

 pillary glands into contact with the fractured edge ; and not pre- 

 cisely upon it, but just within it, depositing the calcareous matter. 

 The reparation proceeded with so much rapidity, that in forty 

 hours four tenths of an inch of shell was added, and then the 

 operation apparently ceased. Another Helix, of a different spe- 

 cies, added one eighth of an inch every two days for nearly a 

 week. Some time after their confinement to the box, several 

 articles were laid upon the mould for their use ; in a few days a 

 large portion of a rotted chip was consumed, a considerable quan- 

 tity of radish was eaten, and a common house-fly, with the ex- 

 ception of the wings, was totally devoured. A patch was eaten 

 out of some crimson colored paper, and the filamentous egesta 

 afterward being beautifully stained with the same color, marked 

 the duration of the digestive process; and evinced that the tin- 

 gent material underwent no perceptible change in the alimentary 

 passage. 



