292 The Transition from Animals to Plants. 



numberless monads, united by a slimy mass, and, at last, 

 after some weeks, the Conferva fugacissima of Lyngbye de- 

 veloped itself in perfection. 



Late observations on the reproductive bodies of some Algae 

 shew that their motion is produced by vibratile cilia, exactly 

 in the same way as in certain animals. But it is exceedingly 

 difficult to imagine the transformation of one real species 

 into another. The same species may assume a variety of 

 forms, according to varying circumstances, and it is highly 

 instructive to observe these changes ; but that the same spore 

 should, under different circumstances, be capable of pro- 

 ducing beings of an almost entirely different nature, each 

 capable of reproducing its species, is a matter which ought 

 not to be admitted generally without the strictest proof. — 

 (Lindley.) 



A few Remarks on Currents in the Arctic Seas. By P. C. 

 Sutherland, M.D. 



The author states, that, during a voyage lately made in 

 the Arctic seas, his attention was arrested by the power ex- 

 erted by refrigeration and congelation, in separating from 

 water any saline ingredients it may contain, and of thus 

 causing disturbances in the mean density of the waters of the 

 ocean, which, after being influenced by currents, can be over- 

 come only by subsequent intermixture with water from other 

 localities where the disturbance in the equilibrium is of an 

 opposite character. He considers that evaporation, which is 

 so active within the tropical and temperate zones, obviously 

 renders the sea more dense by depressing its surface, and 

 thus gives rise to the necessity for currents from the two 

 poles of the earth, where deposition of vapour predominates 

 to a considerable extent over evaporation. This he illus- 

 trates by referring to the constant current from the Atlantic 

 into the Mediterranean, caused by the evaporation in this 

 sea preponderating over the supply of fresh water. He then 

 points out the necessity also of a current out of this sea, in 

 order that its waters, by the constant influx of saline matters 



