562 Notices of Memoirs — Geologists^ Association — 



history ? Mr. Carruthers showed that the vegetable markings pre- 

 served in the earliest rocks are, though indistinct, referred to sixteen 

 species of Alg^. But the nature of the plants -which could flourish 

 in the conditions under which these deep-sea deposits were found, 

 and the changes that have taken place in the primal strata since 

 their deposition, prevent us exjDecting any extensive representation 

 of these early floras. So far as the plant remains go, they meet the 

 requirements of the evolutionist who looks upon the Alg^ as the 

 primeval plants. 



In the phjdogenesis of the Vegetable Kingdom we next come 

 to the evolution of Fungi, Lichens, Mosses, and Hepaticfe, all of 

 which are cellular plants. They came into existence, it is supposed, 

 with the Devonian period — the beginning of the newer Paleeozoic 

 series. As, however, no trace of any of these groups, except the 

 mycelium of one or two species of fungi, has been detected in any 

 of the Palasozoic rocks, they supply no evidence for or against the 

 hypothetical account of their evolution. 



The later Palgeozoic rocks abound in plant remains. The first 

 evidence of land plants on the globe is met with, as far as our 

 knowledge at present goes, in the Devonian rocks. Here the three 

 principal groups of vascular cryptogams appear together in highly 

 differentiated forms. All of them — Ferns, Equisetacece and Lyco- 

 podiacece — possess the same essential structure as their living 

 representatives, and in all the subordinate points in which they 

 differ they possess characters indicative of higher organization, 

 whether in the vegetative or reproductive organs, than are found 

 in existing forms. The three orders appear together in these 

 later Palceozoic rocks, and that not in simpler or more generalized 

 types, but with more varied and more complex structures than 

 are found in their living representatives. Thus, among Ferns 

 there is lost a remarkable group with a fundamentally different 

 stem structure, which was contemporaneous in the Palaeozoic ages 

 with the type of Ferns that have been represented all through the 

 epochs, and are now abundant on the globe. The Equisetacece were 

 represented by a larger number of generic groups than are found in 

 our present Flora. Their stems were arborescent, the leaves large, 

 and their fruit cones protected by special scales, but the spores were 

 similar in size and form to those in the humbler living species, and 

 were even furnished with hygrometric elaters. The Lycopodiacea 

 were also huge trees, and represented by several generic groups. 

 The stem structure, while fundamentally agreeing, like those of the 

 arborescent Equisetacece, with the structure of the stems of their 

 living representatives, was more complex, being suited to their 

 arborescent habits. 



But the Flora of these later Palaeozoic rocks include higher elements 

 even than vascular cryptogams, for in the Devonian series we have 

 coniferous plants, increasing greatly in number and variety in the 

 Carboniferous period ; and in the Calciferous Sandstones at the very 

 base of the Carboniferous measures, there has been found an un- 

 doubted angiospermous plant. The step from the spore-producing 

 cryptogam to the seed-bearing phanerogam is a very great one. No 



