INTBODTJCED PLANTS. 137 



their way into the colony, in a manner apparently accidental. It 

 is true that many of these are what we popularly term "weeds," 

 and those sometimes of a very troublesome and noxious cha- 

 racter, not merely detrimental to the pursuits of agriculture and 

 horticulture, but also containing in some instances deleterious 

 and even poisonous properties. Yet the evil is not unmixed with 

 good, for the spontaneous or fortuitous introduction of some use- 

 less species of a particular genus, is an indication that other 

 species of the same genus, probably containing properties of a 

 useful character, may flourish in the same climate. Thus Nature 

 herself in some instances, seems to point out suitable objects for 

 acclimatisation, or at all events to show the natural families from 

 which we may select individual species with the fairest prospect 

 of adapting them to the country in which we live. But many of 

 these so called weeds are really highly useful to man, some of 

 them being known to possess medical virtues, which may be 

 rendered available with very little trouble, and others being well 

 calculated to serve as esculent vegetables in seasons of scarcity ; 

 whilst some few of them may hereafter afford material for colonial 

 manufacture. Some years ago, the whole family of Algae, or sea- 

 weeds, was pronounced to be useless, and the great poets of an- 

 tiquity, when denouncing anything that appeared to them vile or 

 despicable, were wont to compare it with the vilis or inutilis alga. 

 Indeed, we are credibly informed that not more than fifty or sixty 

 years ago a learned professor, when consulted by one of his 

 pupils respecting some species of Algae, which he had collected on 

 the sea coast, pushed them from him, with the disdainful re- 

 mark, " Pooh ! a parcel of seaweeds ! sir, a parcel of seaweeds !" 

 When we consider the wonderful progress that has been made of 

 late years in the study of Algae, and the useful properties which 

 modern ingenuity has extracted from many of the species, we 

 may be tempted to smile at the ignorance of the learned profes- 

 sor ; but, in so doing, we must beware lest we do not expose our- 

 selves to a similar feeling of contempt from a future generation ; 

 for whilst we have lived to see that the weeds of the ocean, are 

 not merely the " flowers of the sea," but in 'some species highly 

 valuable for commercial and medicinal purposes, posterity may 

 find out that amongst the weeds of the land, which many so un- 

 scrupulously condemn, there are some of the marvellous beauties 



