14 



appear to have been uniform all over the world, even as near 

 the pole as Spitzbergen. Club-mosses and horsetails were 

 trees in bulk and stature, though ungainly to our eyes with 

 their angular forked branching, their spiral rows of stiff 

 leaves, and their grotesque fructification. Mingled with these 

 interesting though unlovely exaggerations were the beautiful 

 lace-like fronds of tree-ferns, as well as a thick carpet of 

 the lowlier species, and also scattered Cycads and Conifers. 

 No birds built their nests in this monotonous jungle, no 

 bees or butterflies lighted up a world destitute of colour 

 and fragrance. But life was, nevertheless, abundant in 

 these thickets, though of an unattractive kind, molluscs 

 and myriapods, and wood-boring beetles. Now, the first 

 thing that strikes us in examining the fossil remains of this 

 flora is the extraordinary abundance and perfection of the 

 impressions of ferns. Their state of preservation is often 

 marvellous. It should be remembered also by those who 

 only see them in cabinets that those collected are but a fraction 

 of those noticed by the observant naturalist. Very often the 

 shale in which they lie buried is so brittle that the collector 

 only catches a passing glimpse of a lovely impression before 

 the matrix crumbles to pieces as he tries to grasp it. It seems 

 impossible in the face of this abundance of remains to deny 

 that at any rate we have here a fairly complete record of local 

 floras. So far as it goes it can be trusted. As the date of the 

 palaeozoic coal measures must in any case be very remote, they 

 evidently supply us witha crucial test for the Theory of Descent. 

 If that theory were true, the lines of vegetable pedigree should 

 be at that time visibly converging. For instance, the three 

 great classes of Vascular Cryptogams ought to be far nearer to 

 each other then than they are now. Is this the case ? Noto- 

 riously the answer is in the negative. Ferns, horsetails, and 

 club-mosses are not only not converging, but are, if anything, 

 further removed from each other than now. The two latter 

 groups then reached their culminating point both in the size 

 of individuals, the number of genera, and the complexity of 

 structure. The Lepidodendrons and Sigillarias had a kind of 

 woody structure feebly represented in their present herbaceous 

 representatives. So also had the huge Calarnites, Calamoden- 

 drons, and Equisetites which have now dwindled down to a 

 solitary genus Equisetutn. The peculiar spores of many of the 

 fossil genera are found in vast abundance, and proclaim unmis- 

 takably their affinity to the modern survivals. 



The ferns still flourish, but at that period they were 

 evidently of greater relative importance than now. At 

 present about forty species grow in the British Islands, but 



