HYDRAID^ : HYDRA. 123 



Trans. Ivii. 430. Ellis and Soland. Zooph. 9. Encyclop. Method. Vers, pi. 67. 

 ^ees' Cyclop. Vermes, pi. 5, fig. 2. — H.grisea, Lin. Syst. 1320. MuU.Yexm. I. ii. 

 14. Couch Faun. Corn. iii. 136. lire's Rutherg. 233. Berk. Syn. i. 222. 

 Blumenh. Man. 295. Lam. Anim. s. Vert. ii. 60. Templeton in Mag. Nat. 

 Hist. ix. 418. — H. brannea, Templeton, \oc. cit. 417, fig. 56. — First sort of Polype, 

 Balxr Polyp. 17, c. fig. — Polypes d'eau douce, M. Edivards Elem. de Zool. 10, 

 fig. 1. 



Hab. Weedy ponds and slowly running waters. 



This does not exceed the H. viridis in size, which it resembles 

 also in its habits and form. It is always of an orange, brown, or 

 red colour, the intensity of the tint depending on the nature of 

 the food, on the state of the creature's repletion, becoming even 

 blood-red when fed upon the small crimson worms and larvae which 

 usually abound in its haunts.* The tentacula in all my specimens 

 have never exceeded the length of the body, are usually seven or 

 eight in number, and taper to the point insensibly. Every part of 

 the body is generative of young, which may frequently be seen hang- 

 ing from the parent at the same time in different stages of their 

 growth. 



3. H. ATTENUATA, ligJit oil-greeTi, the hody attenuated lelow, 

 ivith pale tentacula longer than itself. G. J. 



Plate XXIX. Fig. 1. 



Ilah. Ponds. Yetholm Lough, Roxburghshire. 



Rosel Ins. iii. Polyp, tab. 76 and 77. — Hydra attenuata, Pall. Elencli. 32. Ehrenh. 

 Corall. des roth. Meer. 68. — H. pallens, Turt. Gmel. iv. 692. Lam, An. s. Vert. 

 2de ^dit. ii. 71. 



This, which is represented very exactly in the plates of Rosel's 

 beautiful work quoted above, is a larger animal than H. vulgaris, 

 and comparatively rare, less sensible to external impressions, and of 



* " I have found a bright-red Hydra rather abundant on Putney Heath, near London. 

 It does not much differ, except in colour, from the green one." J. E. Gray in lit. 

 May 6, 1833.— See Trembley's Mem. p. 47, and 128. — M. Laurent has succeeded 

 in colouring Hydr^ blue, red, and white, by means of indigo, carmine, and chalk, 

 " sans penetration reelle dans le tissu. Les bourgeons de ces Hydres ont acquis la 

 meme couleur que leurs meres, tandis que la couleur des ojufs persiste comme dans 

 r^tat naturel, et ne subit aucune modification, quoique I'Hydre mere ait ete nourrie 

 lavant et pendant ce mode de reproduction avec des substances colorantes, et que son 

 coi-ps et ses bras soient tres vivement colores." M. Laurent has also engrafted these 

 variously coloiu'ed Hydris on each other. — Comptes Rendus des Seances de I'Acad. 

 des Sciences, Juin 21, 1841. 



