Natural History of British Zoophytes. 327 



Third sort of Polype, Baker, Polyp. 19 c. fig Le Polype vert, 



Cuv. Reg. Anim. iii. 295 L'Hydre verte, Blainv. Actinol. 494. pi. 



85, fig. 1. 



Hob. Ponds and still waters, common throughout England, and 

 the south of Scotland. In almost all the parishes in the vicinity of 

 Glasgow, Ure. 



The polypes of this species differ from the following, " not only 

 in colour, but likewise in their arms, which were much shorter in 

 proportion to their bodies, capable of but little extension, and nar- 

 rower at the root than the extremity, which is contrary to the 

 other species. Their arms were so short, they could not clasp round 

 a very small and slender worm, but seemed only to pinch it fast, till 

 they could master and devour it, which they did with as much greedi- 

 ness as any. I imagined these polypes owed their green colour to 

 some particular food, such as weeds, &c. and that they would lose it 

 upon being kept to worms ; but I find myself mistaken, for they re- 

 tain their greenness after some months as well as ever, and are now 

 grown of a moderate size, extending sometimes three quarters of an 

 inch ; their arms are also lengthened very much to what they were, 

 and are of a lighter green than the body, their number eight, nine, 

 or ten. The tail is very little slenderer than the body, but more 

 spread at the end than the tails of other kinds." — Baker. 



Pallas says that the offspring are produced from every part of the 

 body, while Blainville thinks he has remarked that they shoot al- 

 ways from the same place, " au point de jonction de la partie creuse 

 et de celle qui ne Test pas." Blainville is candid enough, however, 

 to inform us that Professor Van der Hoeven had made some ob- 

 servations adverse to his opinion ; and our own are certainly in ac- 

 cordance with those of Pallas and of the Professor of Leyden. 



Trembley is careful to tell us that he discovered this species in 

 June 1740, nor can we smile at the particularity of the record when 

 we remember that the discovery is the foundation of his immortal 

 fame. * It was first observed in England in the spring of 1743 by 

 a Mr Du Cane of Essex. It- appears to be a hardy animal. I have 

 kept it for more than twelvemonths in a small vial of water un- 

 changed during the whole of that time, and it remained lively, and 

 bred freely, feeding on the minute Entomostraca confined with it, 

 and which, propagating much more abundantly, furnished a good 

 supply of what was evidently a favourite food. 



2. H. vulgaris, orange-brown or sometimes oil-green ; body 

 cylindraceous ; tentacula 7-12, as long or longer than the body. 



* " Trembley (Abraham), de Geneve, ne en 1710, mort en 1784 ; immortcl 

 parle decouverte de la reproduction du polype." Cuvier, Reg. Animal, iii. 4*22. 



