340 Bibliographical Notices. 



Another most curious variety belonging to tlie same group is given 

 under the name of argentea. It is described as having the cones, 

 and foliage of a splendid silvery hue. A single tree was found 

 by Wittman near the village of Artamin, tvv^o days journey from 

 Batum in Lasisthania. So remarkable is the account of this tree, 

 that had it depended on the single specimen, we should have been 

 inclined to assign its appearance to some accidental circumstance, 

 but Nordmann also saw trees corresponding in colour on the Adshar 

 range. 



We are not informed if the whole range of the Caucasus has been 

 examined, and neither the absolute or relative elevations at which 

 the species are found are perfectly given in this work. The diffi- 

 culty of forming a correct judgement on these points as well as that 

 ascertaining the exact extent of the ranges mentioned is increased 

 by the want of good maps. From the correctness with which the 

 species are described, however, and the care which has been taken 

 to place them before the reader, an approximation may be made 

 to the attainment of this object. In commencing by the south- 

 ern coast of the Black Sea, and following the ascending series, 

 we have successively P. halepensis, P. Laricio (Auctorum), Abies 

 leioclada (var. of Common Silver Fir), A. Nordmanni, A. orientalis, 

 P. uncinata and varieties, lliis arrangement corresponds very nearly 

 with that of th-e Pyrenees, the upper zone being formed of the 

 hardier species of the group of P. sylvestris, with which are mixed 

 the A. orientalis and A. Nordmanni, which attains a very high ele- 

 vation, and is succeeded by A. leioclada, P. Laricio, and P. hale^ 

 pensis, that of the Pyrenees in running a line across Catalonia 

 being P. uncinata and sylvestris, A. pectinata, P. hispanica, P. Pi- 

 naster, and P. halepensis. The chief difference is in the existence 

 of the spruce, which is wanting in the Pyrenees, and the substitu- 

 tion of P. Laricio (or probably taurica), for the hispanica in the 

 middle region. In both chains the Silver Fir predominates over the 

 other species, and in both the larch is wholly wanting. 



In addition to more accurate information as to the actual zones 

 or order of superposition, we should have been glad to know what 

 tree forms the next parallel to the region of firs. In the correspond- 

 ing region of Europe the beech holds that place, and it would be in- 

 teresting to ascertain whether in that part of Asia it retains its posi- 

 tion or is replaced by some other genus. 



The observation of these writers on the wood of A. Nordmanni is 

 extremely valuable, and indicates a point which ought to be attended 

 to in all descriptions of new species when it is possible to obtain it. 



