ODSEUVATIOXS ON MAUINE POT-Yrr'S. 15 



in it made me suppose It to be an Ostrea carinata, but on picking it up I 

 was puzzled, and not knowing what to think of it, submitted it to the 

 inspection of that most excellent naturalist, Mr. John Quekett, of the Royal 

 College of Surgeons. Professor Ovven likewise inspected it, but they were 

 both uncertain as to its nature, conceiving however that it is the cast of some 

 shell. The colour is light gray, the light parts ochre yellow, and not, I think, 

 extending into the Fossil. Perhaps some of the correspondents of "The 

 Naturalist" can throw light upon the subject? 



OBSERVATIONS ON MARINE POLYPES. 



BY THOMAS NIOHOL, ESQ. 

 (In a Letter to a Correspondent. ) 



In reply to your request that I should furnish you with the substance of 

 my observations on the salt-water Polypes in this neighbourhood, I beg to 

 say that it would give me much pleasure to do so, if I could believe they 

 were likely to be of the slightest use. My knowledge of Natural History, 

 as you know, is very limited, and the observations I have made on this 

 particular department have been of so desultory and unscientific a character, 

 that I cannot persuade myself they can be of any value. 



You are aware that great numbers of Marine Polypes are to be found 

 here, their habitat being chiefly on rocky ground between high and low-water- 

 mark. I kept one of them for nearly two years, and several others for 

 sho.-ter periods, in basins of salt water, of course renewing it at intervals of 

 two or throe days. Believing that they must have some more substantial 

 nourishment than the animalculae contained in the water, I tried if they would 

 US3 various kials of fool which I thought might be suitable for them 

 Whilks, Mussels, and Limpets were what I chiefly offered them. If the 

 objeot was dropt near the Polyp, it was invariably seized with its tentacula, 

 and conveyed to its mouth. I have seen a shell nearly as large as the 

 animal itsalf thus s,vallo.ved, distending the body all round. 



Tha Polyp has th3 powjr of locomotion; for, although I never saw any 

 of th3 u in the ast of moving, I have frequently found them at a different 

 side of the basin from that at wh!ch I left them. But perhaps the most 

 interesting circa nstance connected with them was that some of them propagated 

 while in my possession. I had at one time from twenty to twenty-five young 

 ones alive, and probably twice as many gemmules were thrown off in the 

 course of one su-nmer from three individuals. I never saw the gemmules 

 separate themselves from the parent, though I frequently watched for it. 

 Some of the young lived for several weeks, if not months, under my care, 

 • and grew considerably in that time, but most of them died early, which led 

 me to suppose that the side of a basin was not a suitable place for their 

 development. 



