380 Sir J. G. Dalyell on the Reproduction of the 



bone, surprisingly slender for its length, occupies the middle of 

 the rod. 



When inactive, the pennatula is of a flattened figure, not 

 exceeding three lines across. When active, or in a state of 

 intumescence, it would occupy three-fourths of a cylinder nine 

 or ten lines wide — the remaining fourth being nearly vacant, 

 from the flattened side above described. But, in respect to 

 length, we are at this day altogether ignorant of its real di- 

 mensions ; for it is a product never to be obtained entire. 

 Commonly, we find it in fragments seven or eight inches long. 



The largest specimen occurring to me extended twenty-three 

 inches, of which the bone occupied no less than eighteen. But 

 this also was mutilated, for an inch of the bone at one end was 

 bare, and had been so for some time, as the habitation of ano- 

 ther animal was seated on it. From the portion of the flesh 

 lost here, and from that extending beyond the opposite extre- 

 mity, the specimen, entire and vigorous in its native element, 

 could not have been shorter than thirty inches. The bone is pro- 

 bably the longest cylindrical osseous or shelly product known, 

 its length equalling about five hundred times its diameter. 



The Virgularia mirabilis, and that zoophyte to which I for- 

 merly alluded as the Sertularia uber (or argentea, according 

 to the recent learned and useful work of Dr Johnston), both 

 dwelling in the Scottish seas, perhaps exceed the length of any 

 others hitherto distinctly specified. 



The multitude of animals and of organic parts composing 

 them surpass belief. On a specimen of the virgularia seven 

 inches long I computed 130 leaves ; on each leaf 20 hydrse, 

 each with 8 tentacula, and 20 pinnae on each tentaculum ; thus 

 afibrding 416,000 organic parts belonging to the specimen, all 

 subject to volition. But it is probable, that, in the larger spe- 

 cimen above described, the parts under control exceeded a 

 million ! ! ! 



In common with most inhabitants of the deep, the virgularia 

 is strictly a nocturnal product, whose action commences with 

 the approach of night ; for it is then only that its intume- 

 scence, relaxed throughout the day, and the vigour of its 

 numerous hydi-se, are manifested. 



Whether it enjoys a locomotive faculty, or whether, growing 



