Edinburgh. The plants of this family are chiefly 

 natives of countries near the Equator, many of them 

 arborescent and of considerable size. 



The flora of the succeeding permian age is marked by 

 the preponderance of cycads and conifers, also 

 ferns similar to those now limited to the southern 

 hemisphere. Several plants now disappear. 

 Sigillaria,) Aster ophyllites^ most of the woody 

 Eyuisetacece and Lepidodendra, whose cones surpassed 

 in elegance of structure those of the conifer, which 

 they resemble in form, while the cryptogamic organi- 

 zation of their fructification and the separate grouping 

 of the male and female spores approach the recent 

 Isoetes, which, as is well known, now only grows at the 

 bottom of lakes. Europe, which was, until the end of 

 this age, an archipelago of islands, gradually became 

 united so as to form a continent. Cycads and conifers 

 continued to flourish ; angiosperms, which now comprise 

 more than nine-tenths of living plants, had not then 

 appeared on the earth's surface. The cycads do not 

 differ from those which now grow in the vicinity of 

 the tropics ; many of the conifers were of great height, 

 allied to the Aracaurias and Cypressinece. Brachy- 

 phyllum, whose leaves were reduced to simple 

 mammilated scales, are especially distinctive of this 

 period. 



At the summit of the Hochrnad, half-way up the 

 Blumenstein, (a liassic formation), has been found, a 

 cycad Zamites gracilis^ Kurr, also two conifers Wid- 

 dringtonia liassica, Kurr, and Thuites fallax, Herr, 



