460 Retrospective Criticism. 



and the other l^clt'tfi^s^f^ip^P^^^ applied to its opposite one, having 

 the loose pieces of paper and' pfants between them. After which one or 

 two of the books should be placed on the outside of the paper, and remain 

 there until as many other plants as are intended to be preserved have been 

 prepared in like manner. A layer of sand, an inch deep, should then be 

 put into the box, and afterwards one of the plants, with the books placed 

 upon it, which last should be removed after a sufficient quantity of sand is 

 put upon the paper, to prevent the plant from varying its form. * All the 

 other plants may then be put into the box in the same manner, with a 

 layer of sand about an inch thick between each, when the sand should be 

 gently pressed down by the foot, and the degree of pressure, in some mea- 

 sure, regulated by the kind of plants in the box. If they are stiff and firm, 

 as the holly or furze, much pressure is required. If tender and succulent, a 

 less degree is better, for fear of extravasating the juices^ which would 

 injure the colour of the plant ; but particular care should be taken to make 

 a sufficient degree of pressure upon the expanded blossoms of plants, that 

 they may not shrivel in drying. The box should then be carefully placed 

 before a fire, with one side a little raised, or occasionally flat, as may be 

 most convenient, alternately changing the sides of the box to the fire, 

 twice or thrice a day ; or, when convenient, it may be put into an oven in 

 a gentle heat. In two or three days the plants will be perfectly dry. The 

 sand should then be taken out with a common plate, and put into a spare 

 box, and the plants carefully taken out also, and removed to a sheet of 

 writing paper." (Whatelei/yin Witkenng^s Botmij/,\o[.i. p. 28.) 



The Practice of Travellers^ in disseminating Exotics among our Indigenous 

 Plants. — Sir, I beg to call your attention to the following extract from 

 the valuable and highly interesting new edition of the Ari^angement of British 

 Plants^ in which a practice, worthy surely of severer reprobation, is thus 

 courteously condemned: — Additions and corrections, p. 442. vol. iv. 

 " Antirrhinum Cymbal aria. In reference to the note, add : Since writing 

 the above, we observe an acknowledgment, on the part of a certain enthu- 

 siastic naturalist (see Mag. Nat. Hist., Vol. I. p. 400.), of his having sown 

 the plant in question on the rock near Barmouth ; a practice from which 

 other similar errors have originated, and concerning which,, as tending to 

 create confusion in science, among those especially who would wish to see 

 . the stations of our native plants defined with accuracy, there can he hit 

 one opinion. E." - — ^ Your insertion of this notice may be the means of 

 deterring other travellers from conduct so reprehensible, and will moreover 

 oblige — A Constant Subscriber. Bristol , May 29. 1830. [Is not the beauti- 

 fying of our wild scenery a thousand times more valuable than this exclu- 

 sive devotion to a single science ?] — Cond. 



Disseminating Exotics, and mistaking them for British Plants. — An 

 impression was formerly too prevalent, that the Flora of the British 

 islands had been so fully investigated, that no new discoveries could be 

 made; and this misconception has been strengthened by the deservedly 

 unsuccessful attempts to introduce mere varieties as species, through the 

 medium of the later editions of Withering' s Botanical Arra7igement. But a 

 new and more auspicious era has now commenced; and while the taste for 

 natural science is daily augmented and diffused by the zeal of its professors 

 in the various universities of the three kingdoms, the recent additions to 

 our British plants in Dr. Hooker's newly published Flora, as well as those 

 which had but a short time previously appeared, for the first time, in the 

 English Flora of Sir J. E. Smith, are sufficient to show that our own 

 country may still possess 



" * Those of the genus Potamogeton, and others of the same kind, ought 

 to be put into the sand without loss of time, and well pressed, otherwise 

 they are apt to dry too fast, and shrivel." 



