PAL.EOPHYTOLOGY : FOSSIL PLANTS. 273 



rocks, marine plants and naiades predominate. Thus, the 

 forests of cycadese of the oolitic period had long disappeared, 

 and in the oldest groups of the tertiary formation this 

 family is very subordinate to the coniferse and the 

 palms. ( 3 3i) 



The lignites, or beds of brown coal, which are found in 

 each division of the tertiary period, contain, amongst the 

 earliest land cryptogamia, some palms, a great number of 

 coniferae with well-marked annual rings, and arborescent 

 forms (not coniferous) of a more or less tropical character. 

 The middle tertiary period is marked by the re-establish- 

 ment, in full numbers, of the families of palms and cycadese, 

 and, finally, the most recent shews great similarity to our 

 present vegetation, exhibiting suddenly and abundantly 

 various pines and firs, cupuliferse, maples, and poplars. 

 The dicotyledonous stems in lignite are occasionally charac- 

 terised by colossal size and great age. In a trunk found 

 near Bonn, Noggerath counted 792 annual rings. ( 332 ) In 

 the turf bogs of the Somme, at Yseux near Abbeville, a 

 trunk of an oak tree has been found above fourteen feet in 

 diameter, which is an extraordinary thickness for the extra- 

 tropical parts of the old continent. It appears from G op- 

 pert' s excellent investigations that " all the amber of 

 the Baltic comes from a coniferous tree, which, judging 

 from the remains of its wood and bark at different ages or 

 stages of growth, seems to have been a peculiar species, 

 approaching nearest to our white and red pines. The 

 amber tree of the ancient world (Pinites succinifer) was far 

 more resinous than any conifer of the present period, the 

 resin being deposited not only as in our present trees within 

 and upon the bark, but also in the wood itself, following 

 the course of the medullary rays, which, as well as the ceils, 



