DISTRIBUTION OF CONIFEROUS PLANTS. 45 



years reckoned from a fixed epoch, but from an examination of the 

 fossil remains, and from other data, they have ascertained which strata 

 are of earlier formation, and which are more recent. They have also 

 shown that, from the remains of plants and animals found in the 

 different strata, the simplest forms alone of organic life occur in the 

 more ancient strata, and there has been a gradual developement through- 

 out the series, from the simpler forms to the higher and more 

 complex organisations met with in the more recent strata, among which 

 existing species begin to make their appearance. 



The oldest vestiges of the vegetable world that hav ebeen preserved, 

 occur in the lower strata of the Primary or Palaeozoic Age, called the 

 Silurian System.* They consist only of a few marine Algse (Seaweeds). 

 In the Devonian System vegetable remains are more abundant. Land 

 plants make their first appearance, and among them Coniferae and a few 

 Cycads. "Vegetable life had extended over the earth in a variety of 

 forms, but the aspect of this period, as also of the next in succession, 

 must have been uniform and monotonous to an extraordinary degree." t 



In the Carboniferous period (Coal Measures), vegetation attained a 

 luxuriance far surpassing that at present existing. Over five hundred 

 species have been described, "which may perhaps be a fragment only of 

 the entire flora, but they are enough to show that the state of the 

 vegetable world was then entirely different from that now prevailing." J 

 This vegetation, which formed the true primeval forests of the earth, 

 consisted of gigantic Club Mosses (Sigillariae, Lepidodendrse, &c), Horse 

 Tails, called Calamites (Equisetaceas), and Coniferae, with a dense under- 

 growth of Perns, which in this period attained a .special developement. 

 "The Coniferous trees are referred to five genera, the woody structure 

 of some of them showing that they were allied to the Araucaria 

 division of Pines more than to any of our common European Pirs. 

 Many, if not all of them, differed from living Coniferse in having 

 large piths." The Sigillarias and Calamites appear to have been quite 

 distinct from all tribes of now-existing plants. "That the abundance 

 of Perns implies a moist atmosphere is admitted ; but no safe con- 

 clusion," says Dr. Hooker, "can be drawn from Coniferee alone, as they 

 are found in hot and dry, and in cold and dry climates, in hot and 

 moist, and in cold and moist regions. In New Zealand the Coniferse 

 attain their maximum in numbers; many species of Perns flourish 

 there, some of them arborescent, together with many Lycopods, so that 

 a forest in that country may make a nearer approach to the Carboni- 

 ferous vegetation than any other now existing on the globe. § The 

 uniformity of the vegetation of the period, which it is computed must 



* For the explanation of these and other terms of the like kind used in the sequel, the 

 reader is referred to works on Geology. 



t Thome", p. 420. See also Sir C. Lyell's Geology, p. 54-1. 

 I Sir C. Lyell, Geology, p. 466, § ^dem, 476. 



