Natural History of British Zoophytes. 325 



to me not altogether unwarrantable to infer a like temporary exist- 

 ence and revival in those of the Sertulariadse from a reflection on the 

 experiments of Mr Lister, — incomplete certainly, but which prove 

 that under certain circumstances their polypes disappear by a pro- 

 cess of internal absorption,* and under convenient circumstances 

 would have been renovated, as I have witnessed in similar expe- 

 riments. \ Had these singular facts been known to Linnseus, how 

 eagerly and effectively would he have impressed them into the sup- 

 port of his favourite theory ! Like the flowers of the field the heads 

 or " flores" of these polypidoms expand their petalloid arms, which 

 after a time fall like blighted blossoms off a tree ; — they do be- 

 come " old in their youth," and rendered hebetous and unfit for duty 

 or ornament by age or accident, the common trunk throws them off, 

 and supplies its wants by ever-young and vigorous growths. " Ad- 

 miranda tibi levium spectacula rerum." The phenomena are of those 

 which justly challenge admiration and excuse a sober scepticism, so 

 alien are they to all we are accustomed to observe in more familiar 

 organisms ; but besides that faithful observation renders the facts un- 

 deniable, a reflection on the history of the Hydra might almost have 

 led us to anticipate such events in the life of these zoophytes. 

 " Verily for mine owne part, the more I looke into Nature's workes, 

 the sooner am I induced to beleeve of her even those things that 

 seem incredible." 



I arrange the British species of this order under the following fa- 

 milies and genera : 



Family I. HYDRAIDiE. 



Polypes viviparous, the young pullulating from the body of the 



parent. 

 1. Hydra. Polypes naked, single, locomotive. 



* Phil. Trans. 1834, p. 374, 376. 



f On Saturday, May 28th 1837, a specimen of Campanularia gelatinosa was 

 procured from the shore, and after having ascertained that the polypes were ac- 

 tive and entire, it was placed in a saucer of sea-water. Here it remained un- 

 disturbed until Monday afternoon, when all the polypes had disappeared. Some 

 cells were empty or nearly so, others were half- filled with the wasted body of 

 the polype, which had lost, however, every vestige of the tentacula. The water 

 had become putrid, and the specimen was therefore removed to another vessel 

 with pure water, and again set aside. On examining it on the Thursday (June 

 1st) the cells were evidently filling again, although no tentacula were visibly 

 protruded, but on the afternoon of Friday (June 2d) every cell had its polype 

 complete, and displayed in the greatest perfection. 



VOL. II. NO. 10. Y 



