344 PHYSIOGNOMY OP PLANTS^. 



tion, of the birdumd the common fir in a part of the Swiss Alps, 

 on the Grimsel. The fir (Pinus sylvestris) extends to 5940, and the 

 birch (Betula alba) to 6480 French (6330 and 6906 English) feet; 

 above the birches there is a higher line of Pinus cembra, whose 

 upper limit is 6890 (7343 English) feet. Here, therefore, we have 

 the birch intervening between two zones of Coniferae. Accord- 

 ing to the excellent observations of Leopold von Buch, and the re- 

 cent ones of Martins, who also visited Spitzbergen, the following 

 geographical limits were found in Lapland : , Pinus sylvestris extends 

 to 70; Betula alba to 70 40'; and Betula nana quite up to 71; 

 Pinus cembra is altogether wanting in Lapland. (Compare linger 

 iiber den Einfluss des Bodens auf die Vertheilung der Gewachse, 

 s. 200 ; Lindblom, Adnot. in geographicam plantarum intra Sueciam 

 distributionem, p. 89; Martins, in the Annales des Sciences natu- 

 relles, t. xviii. 1842, p. 195.) 



If the length and arrangement of the needle-shaped leaves go far 

 to determine the physiognomic character of Coniferse, this character 

 is still more influenced by the specific differences in the breadth of 

 the needles, and the degree of development of the parenchyma of 

 the appendicular organs. Several species of Ephedra may be called 

 almost leafless; but in Taxus, Araucaria, Dammara (Agathis), and 

 the Salisburia adiantifolia of Smith (Gringko biloba, Linn.), the sur- 

 faces of the leaves become gradually broader. I have here placed 

 the genera in morphological succession. The specific names first 

 chosen by botanists testify in favor of such a succession. The Dam- 

 mara orientalis of Borneo and Java, often above ten feet in diame- 

 ter, was first called loranthifolia ; and Dammara australis (Lamb.) of 

 New Zealand, which is 140 (149 English) feet high, was first called 

 zamsefolia. In both these species of trees the leaves are not needles, 

 but " folia alterna oblongo-lanceolata, opposita, in arbore adultiore 

 saepe alterna, enervia, striata." The under surface of the leaves is 

 thickly set with porous openings. This passage or transition of the 

 appendicular system from the greatest contraction to a broad-leaved 

 surface, like all progression from simple to compound, has at once a 

 morphological and a physiognomic interest (Link, Urwelt, th. i. 

 18B4, s. 201-211). The short-stalked, broad, cleft leaf of the 

 Salisburia (Kampfer's Gringko) has also its breathing pores only on 



