Zoological Bystems. 17 



state of the crops and of vegetation. It may be expressed in 

 the following formulary ; the wind exercises a direct action 

 on vegetables, often ^gv^ injurious, and which ought to be 

 carefully distinguished from climatological action. It is 

 against this direct action, that curtains of wood, by forming 

 a shelter, are especially useful. 



The direct influence of the wind, on the phenomena of vege- 

 tation, is nowhere more strikingly exemplified than in the 

 Isle of France. The south-east wind, very healthy both for 

 man and animals, is, on the contrary, a perfect scourge to 

 the trees. Fruit is never found on the branches directly ex- 

 posed to this wind ; none is to be found but on the opposite 

 side. Other trees are modified even in their foliage ; they 

 have only half a head, the other has disappeared under the 

 action of the wind. Orange and citron trees become superb 

 in the woods. In the plain, and where they are without shel- 

 ter, they always continue weak and crooked.* 



Ow the Ichthyological Fossil Fauna of the Old Bed Sandstone. 

 By Professor Agassiz. 



The greater part of zoological treatises, which embrace 

 the natural history of the animal kingdom in its whole ex- 

 tent, represent animals as forming a continuous series, set- 

 ting out with the Zoophytes, and terminating in Man, pass- 

 ing through the intermediate types of radiata, mollusca, ar- 

 ticulata, and vertebrata. Sometimes they place the mol- 

 lusca, at other times the articulata, in the second or third 

 rank, according to the ideas their authors have formed of the 

 superiority of these types. Others, while they admit a gra- 

 dation of animals from the invertebrate to the vertebrate, do 

 not uniformly construct an ascending scale of the former 

 in order to reach the latter, but place the radiata in the in- 

 ferior degree of organization, and, by diverging in two dif- 

 ferent directions, pass to the mollusca and articulata, wiiich 

 they regard as parallel groups, afterwards converging to- 



* Annuaire pour I'an 1846. 

 VOL. XLI. NO. LXXXI. — JULY 1846. B 



