COLOUBj DISTRIBUTION, ETC. 23 



winter or a brilliant burning summer do not act so di- 

 rectly nor with such force on Sea-weeds as they do on 

 gardens and cornfields. Nevertheless the one will some- 

 times hinder the development of those more southern 

 species which ordinarily attain a modified maturity on 

 our shores ; and the other, on the contrary, will force 

 them into the full perfection which characterizes them 

 in their more genial home. 



" The penetrative Sun, 

 His force deep darting to the dark retreat 

 Of vegetation, sets the steaming power 

 At large." — Thomson. 



