chap, cxiii. coni'ferje. ^bie'tina:. 2151 



the cones of all the varieties of P. sylve'stris terminate in surfaces having 

 more or less the appearance of a depressed pyramid; those of all the varieties 

 of P. Laricio have a smooth lip, more or less protruding, and terminating 

 in a depressed point ; those of all the varieties of P. Pinaster terminate in 

 a strong woody pyramidal point; and those of all the varieties of P. TaeMa 

 in a slender sharp prickle, turned upwards or downwards. The cones of 

 different varieties of what we consider as the same species vary much in 

 size ; and, as these variously sized cones are generally reproduced from 

 seed, the plants bearing them have been usually treated as distinct spe- 

 cies. We do not, however, consider the fact of the seed of large-coned 

 varieties producing plants bearing large cones, any more a proof that the kind 

 is a species, than we do that of seedlings from the seeds of a large apple pro- 

 ducing trees bearing large apples, a proof that the particular kind of apple is 

 a species distinct. from apple trees bearing small apples. The cones of P.(s.) p. 

 Mughus are twice the size of those of P. (s.) p. pumilio ; but in other respects 

 the plants are hardly distinguishable. Perhaps we shall be told that the com- 

 parison between pine trees and apple trees is not a fair ground of argument ; 

 because the apple tree is in a state of culture, and far removed from its natural 

 habits ; but to this we answer, that the same effects as those produced by 

 culture in the apple tree, are produced by a variety of geographical and phy- 

 sical circumstances in the pine tree ; and of this the two above-named 

 varieties of P. sylvestris may be cited as a proof. 



The leaves of all the species of pines may be classed according to the num- 

 ber in a sheath ; and this is a most convenient mode of determining the groups 

 and even the species, in the case both of young plants, and of trees without 

 cones. All the European species, with the exception of P. Cembra, have only 

 2 leaves in a sheath, and most of the Asiatic, Mexican, and Californian kinds 

 have 3, 4, or 5 leaves ; while those of the United States and Canada have, for 

 the most part, 3. The leaves vary in length in different species ; but much less 

 so in the varieties of the same species than might be imagined. Thus, in all 

 the varieties of P. Laricio the leaves are nearly double the length of those of 

 P. sylvestris. 



Pinus. In studying this genus, and arranging the kinds according to their 

 buds, cones, and leaves, we consider P. sylvestris, P. Laricio, P. Pinaster, 

 P. Pinea, P. halepensis, and P. Cembra, as the principle European species, and 

 the other European kinds as only varieties of them. P. australis, P. TV da, 

 P. Banksiawa, P. inops, P. pungens, and P. tftrobus, we consider as the prin- 

 cipal species of North America. P. Sabiniawa, P. ponderdsa, and P. insignis 

 are the principal species of California. P. Lambertiana and P. monticola 

 also from California, and P. excelsa from Nepal, appear to be only varieties 

 of P. Strobus. The most remarkable species from Nepal is P. Gerardiawa, 

 which has straight stiff leaves like those of P. Pinea, but with caducous 

 sheaths. 



^4 v bies is a genus of which there are so few species, that it is attended with 

 no great difficulty. A. rubra, A. nigra, and A. alba are probably only differ- 

 ent forms of one and the same species. A. Smithmwa may possibly be a variety 

 of A. excelsa, and A. dumosa of A. canadensis. A. Douglas? and A. Menziesie 

 appear specifically distinct, but there are only very small plants of the latter 

 in this country. One of the most remarkable species of J v bies, from Cepha- 

 lonia, which has lanceolate and sharp-pointed leaves, like those of an arau- 

 caria, has just (1837) been introduced. 



Picea is a very easy genus ; P. balsamea, Frasen, and Pichta are probably only 

 varieties of one species ; and, though P. Webbzawa has purple cones, we doubt 

 whether it can be considered more distinct from P. pectinata than Tilia. 

 grandifolia is from T. parvifolia. The colour of the cones in the ^bietinae 

 has no claim to be considered a specific distinction ; because in all exten- 

 sive woods of one species, such as of P. sylvestris and iarix europae^a in 

 Scotland, they will be found to vary considerably. 



7/arix. It appears very doubtful to us, whether there are more than one 



