254 BEIEP REMAEKS. 



will be found suitable for them. The surface of the pots should be 

 kept moist, and as soon as they begin to emerge from the soil, frequent 

 slight syringings should be afforded them. When the plants are coming 

 into flower, they should be gradually exposed to a lower temperature, 

 which will be the means of keeping them longer in perfection ; or if 

 they are intended for bouquets, they will not flag so soon as when they 

 are cut from a stove. Pharo. — Gardener's Chronicle. 



Genus and Species of Plants. — What is a genus, or what is a 

 species, is a point upon which scarcely two botanists are agreed at the 

 present day. With regard to the former, however much it may be 

 necessary to subdivide in a system comprehending the known plants of 

 the whole world, so as to retain only a limited number of species in 

 each genus, the same does not apply to a local Flora ; and it is there 

 preferable to constitute sections or subgenera, particularly when the 

 limiting characters are inconstant, difiicult, or obscure. A species 

 cannot be so treated ; it is formed by our Maker as essentially distinct 

 from all other species, as man is from the brute creation ; it can 

 neither for convenience be united with others, nor be split into several; 

 l>ut the difficulty is to ascertain what is such a primitive or natural 

 species, and it is here so great a difference of opinion exists. Some 

 pronounce a species to be distinct if it presents a different habit or 

 appearance to the eye, particularly if this be constant, although often 

 indefinable ; olhei's consider it a species, although exhibiting no differ- 

 ence of aspect, provided it can be defined, even although the differences 

 are so minute that they can be detected only by the microscope ; while 

 a third party are of opinion that the validity of a species may be tested 

 by cultivation. The authors are not inclined to believe that any one 

 of these tests is sufficient. Of all the works of creation, we have a 

 specific account only of man ; but as the others appear to be formed 

 on the same plan, there is a strong presumption in favour of those 

 arguments which assimilate the speoies of plants to what we know of 

 the human race. With regard to mankind, it is universally acknow- 

 ledged that there now exists so great diversity between an inhabitant 

 of the torrid and an inhabitant of the frigid zone, and even of any one 

 part of the globe and of another, tiiat it can only be accounted for on 

 the principle that each succeeding generation has a tendency to recede 

 more and more, in general appearance, from the original type ; and if 

 we apply this to the vegetable kingdom, we must at once allow that, 

 although cultivation may sometimes in a single year or two satisfac- 

 torily show that two supposed species are the same, a thousand years' 

 cultivation cannot prove them distinct. The more we cultivate a 

 plant, or the more it is limited in its wild state to a particular climate 

 or place of growth, the more permanency is given to the peculiarities 

 of what was originally derived from the same root, or even seed-vessel, 

 of another afiparently widely different form. Hence a rare mountainous 

 plant may frequently be a mere alpine permanent state of some common 

 lowland species, or a Swedish species the more northern race or state 

 of a southern one ; and it is from this cause that we see in our gardens 

 so many called species (as in the genus Achillea), which cannot now 

 be referred satisfactorily to any of the wild cues, although primarily 



