260 VIEWS, &C. PHYSIOGNOMY OF PLANTS. 



fresh condition.* In the far north too, the Greenland 

 Umbellaria Grcenlandica has been brought up alive by 

 whale fishers from a depth of 236 fathoms.f The same 

 relation between species and locality is met with among 

 sponges, which however are now regarded as belonging more 

 to plants than to zoophytes. On the shores of Asia Minor, 

 the common marine sponge is brought up from depths varying 

 from 5 to 30 fathoms, although one very small species of the 

 same genus is only found at a depth of at least 180 fathoms. | 

 It is difficult to divine what hinders the Astrajas, Madrepores, 

 Ma3andrinas, and the whole group of tropical phyto-corals, 

 which are capable of constructing large cellular calcareous 

 walls, from living in very deep strata of water. The decrease 

 of temperature is very gradual, the diminution of light nearly 

 the same, and the existence of numerous Infusoria at great 

 depths of the Ocean proves that there cannot here be any 

 deficiency of food for polyps. 



In opposition to the hitherto generally adopted opinion 

 respecting the absence of all organisms and living creatures 

 in the Dead Sea, it is worthy of notice that my friend and 

 fellow-labourer, M. Valenciennes, has received, through the 

 Marquis Charles de 1'Escalopier, and through the French 

 Consul Botta, beautiful specimens of Porites elongata from 

 the Dead Sea. This fact is the more interesting, because this 

 species is not found in the Mediterranean, but only in the Red 

 Sea, which, according to Valenciennes, has but few organisms 

 in common with the Mediterranean. As a sea-fish, a species 

 of Pleuronectes, advances far into the interior of France, and 

 accustoms itself to gill-respiration in fresh water, so also does 

 a remarkable flexibility of organization exist in the above- 

 mentioned coral-animal (Porites elongata of Lamarck), as the 

 same species lives both in the Dead Sea, which is super- 

 saturated with salt, and in the open ocean near the Sechelles 

 Islands. 



According to the most recent chemical analyses of the younger 



* See Eoss, Voyage of Discovery in the Southern and Antarctic, 

 Regions, vol. i. pp. 334, 337. 



f Ehrenberg, in the Abhandl. der Berl. Akad. ays dem J. 1832, 

 a. 430. 



% Forbes and Spratt, Travels in Lycia, 1847, vol. ii. p. 124. 



See my Asie centrale, t. ii. p. 517 



