68 OYSTERS, AND ALL ABOUT THEM. 



been sometimes supposed. They declared, for instance, 

 that there oysters might be seen growing on trees ; and the 

 statement was not merely denounced as incredible, but as 

 absolutely false. But, as many facts attested by Bruce met 

 with direct contradiction, yet have since been placed 

 beyond all doubt by the testimony of numerous and unim- 

 peachable witnesses, so has it proved with the one just 

 mentioned. How wise is it, then, to guard against 

 extremes ! The scepticism on which some pride them- 

 selves is closely allied with the credulity they affect to 

 despise. Many are the statements of science which are 

 not merely startling but confounding ; they may even 

 involve what we have previously deemed to be impossible ; 

 yet the more we listen to them intelligently, the more shall 

 we be disposed to take up a central position far away from 

 the two opposite evils. 



If we do so in the present instance, we shall find that 

 the common mangrove, and also others of its tribe, (c] are to 

 be observed all along the shores of the tropics, both in the 

 new and the old world, rooting themselves in the mud 

 the very soil for which they are expressly designed and 

 forming dense forests, even at the verge of the ocean, and 

 below high-water mark. Peculiar as the plants of this 

 family are for the germination of their seeds, even while 

 attached to the branches, they are equally so for the 

 numerous root-like projections which serve as so many 

 supports to the stem ; hence, on the retiring of the tide, 

 and on the margins of the great rivers which are fringed 

 by these trees in tropical climates, the stems may often be 

 seen covered with oysters. The species thus found is 

 expressly called the " tree oyster." (d] The negroes living 



(c) Rhizophorese. 

 (d) Ostrea arborea. 



