PALAEONTOLOGY 63 



true Palaeozoic epoch. From the point of view of the 

 fossil botanist this epoch is unique because it includes 

 the period of the Coal Measures. During this period in 

 Europe there was not only a remarkable tendency to 

 produce coal in a number of successive layers, but the 

 plants which provided the necessary vegetable matter 

 for the coal layers were fortunately preserved in large 

 numbers. All the different varieties of fossils casts, 

 impressions, and very wonderful petrifactions are 

 abundant in deposits of this age. We have, conse- 

 quently, a more complete knowledge of the flora of the 

 Coal Measures than we have of any other epoch, ex- 

 cepting that of the present day. All the genera and 

 species from these beds are not only extinct but are 

 fundamentally different from forms now living. Many 

 great volumes have been written on the plants of the 

 Coal Measures, but we must only glance at one or two 

 of the more interesting of them. Those highest in the 

 scale were probably the fossils well known as Cordaites. 

 They were tall trees with solid woody shafts and long, 

 sword-like leaves, and they bore seeds in cones which 

 were more complex than those of the living family 

 which is least remote from them, the Monkey-puzzles. 

 But the majority of the large tree-like forms of these 

 times were much more remote from any living trees 

 than were the Cordaites. The two genera, Catamites 

 auJ. Lepidodendron, were large trees with very numerous 

 different species. Their shafts were sometimes as 

 much as three or four feet in diameter, and many speci- 

 mens have been recorded that show that they reached 

 the height of tall forest trees. The bulk of the stem 

 was composed of softer tissue than is usual now in any 

 self-supporting tree, but there was a quantity of the 

 regularly developed secondary wood which is now only 



