THE FLOEA OF PLYMOUTH. 



19 



spots where there is good reason to suppose houses have stood, 

 would, notwithstanding its propagating itself readily in such places, 

 be a sufficient argument for placing it in the category of denizens. 

 Supposing all remains of a house had been obliterated, the presence 

 of two or three such species in one locality would lead a judicious 

 botanist to conclude at once that they mark the site of an old 

 garden, or had been introduced in some way. Should they be 

 plants that are still objects of cultivation, or historical evidence 

 show them to have been this, the case would be still stronger 

 against their being considered indigenous. When, too, a species is 

 found only sparingly a great distance beyond the bounds of its 

 general range, its occurrence, as a native, where it so sparingly 

 appears would be held to be very improbable geographically, unless 

 the spot afforded peculiar physical features adapted to its require- 

 ments, not possessed by the intervening country. 



The love of flowers seems natural to man. We see the child in 

 the nurse's anns trying to get into its baby grasp every bright 

 flower it sees near it. It will pull them to pieces certainly, but it 

 is its regard for them that makes it do so ; a curiosity, we may well 

 believe, to know as much about them as its dawning intellect will 

 enable it to discover — consequently, it is not surprising to find the 

 cultivation of flowers, as objects of beauty, prevailing in various 

 parts and at different ages of the world. 



Among the denizens apparently introduced for their uses (ex- 

 cluding medicinal, superstitious, or ornamental ones) are several 

 forest and fruit trees, two or three fruit bushes, and some potherbs. 



Questions as to the indigenous character, or period of introduction 

 of our trees must, it is imagined, be of great importance to his- 

 torical painters in cases where they have to introduce scenery into 

 their works. 



It is extremely difficult to assign a position to several fruit trees — 

 whether to regard them as the originals of cultivated species, or to 

 consider them as the degenerated produce of these — individuals 

 reverting to a natural condition from a cessation of man's care. 



Among the herbaceous denizens introduced either for food, 

 or for domestic, medicinal, or ornamental purposes, the lecturer 

 placed Saponaria officinalis, L. ; Srmjrnium Olusatrum, L. ; Cheno- 

 podium Bonus -IlenricuSy L. ; Ilellehoriis viridis, L.; Chelidonium 

 maj'us, L. ; Althcca officinalis, L.; ^gopodium Podagraria, L. ; 

 Samhucus Ehulus, L.; some Mentha; Narcissus hijiorus, Curt., &c. 



