GEOGRAPHY OF PLANTS. 



265 



plants, that the lower the organization of the body is, the 

 more generally is it distributed. As infusory animalculae are 

 produced in all zones, when the same conditions exist ; we 

 find, in the same manner, that Fungi, Sponges, Algae, and 

 Lichens, and even Musci frondosi and hepatici, are distri- 

 buted every where upon the earth, in the sea, and in the wa- 

 ters, when the same circumstances propitious to their produc- 

 tion occur. We have seen that the idea of genera and 

 species can be applied with so much less strictness, the less 

 perfect the vegetable is ; and hence, although the same or si- 

 milar forms of Conyomici, Nematomici, Gastromici, and 

 Sponges, are produced in all zones, we cannot pronounce in 

 all cases respecting the identity 'of the species. If travellers had 

 not so much neglected the imperfect plants of foreign coun- 

 tries, this assertion might easily have been proved by innu- 

 merable testimonies. But we must receive with caution 

 and limitation, even what they have told us respecting the 

 growth of common European cryptogamous plants in the 

 most distant regions and waters of the earth, because many 

 of these travellers had no exact knowledge of the crypto- 

 gamous plants. The most distant countries of the earth, Eu- 

 rope and New Holland, the inhabitants of which are anti- 

 podes to each other, have, according to the testimony of 

 Brown, a witness of the best information and highest credit, 

 a considerable number of Lichens, almost indeed two-thirds 

 of those that have hitherto been discovered in New Holland, 

 of the same species with those that exist in Europe. Of the 

 Musci hepatici and frondosi, nearly one-third belong equally 

 to New Holland and to Europe. And, with respect to the 

 Algas, not only Confervse, but Fuci, are common to the 

 most distant seas. Laminaria Jgarum, Lam., for instance, is 

 found in Greenland, in Hudson's Bay, in K'amtschatka, and 

 in the Indian Ocean. Halidrys siliquosa, Lyngb., Spharo- 

 coccus ciliatus, Ag., and many others, have a distribution 

 equally extensive. 



The Naiadae and Rhizospermae also are found in the same 

 manner almost in all waters, as the Marsilea quadrifoUa, 

 Zostera marina.^ and the native l*otamogetons and Lemnas 



