12G 



HARDWICKE'S SCIENCE-GOSSIP. 



represented on the Continent by the beds of the 

 Paris basin, famous to geologists as having yielded 

 to Cuvier the first materials for the young science 

 of comparative anatomy. 



Taking the upper Eocene strata in England, you 

 find a gradual transition from purely marine to 

 purely fresh-water conditions, the Headon series 

 containing shells and other organic remains usually 

 found under both circumstances. The Bracklesham 

 sands are crowded with fossil shells, chiefly of Turi- 

 tella, indicating how slowly such beds must have 

 been formed, aud how suitable was the ancient sea- 

 bottom to the luxuriant development of these 

 molluscs. I should also meution that underneath 

 the London clay proper is a series of strata, chiefly 

 of sands and gravels, ranging to a total thickness of 

 nearly two hundred feet. My hearers who have 

 carefully studied the geology of older formations, 

 will see that a marked feature about these newer 

 deposits is their very local extension. Whereas the 

 older beds are almost world-wide in their distribu- 

 tion, the newer are so limited that it is very difficult 

 to correlate them in different countries. Again, the 

 principle of geographical distribution of animals 

 aud plants is felt more palpably in these newer than 

 in the more ancient organisms. In the old rocks 

 all over the world you see fossils common to them, 

 but every stratum in the more recent deposits 

 is marked by its own suite of shells, &c. ; just as 

 every sea now possesses its own peculiar fauna. • 



I was formed along the bottom of the sea, at no 

 great distance from land, aud yet far enough off for 

 the sediment brought down by the rivers to have 

 bad its coarser particles precipitated before it 

 reached the area over which my parent stratum was 

 laid. Consequently, the muddy matter which there 

 fell to the bottom was of a very impalpable charac- 

 ter. The distant land was watered by large rivers, 

 whose mouths debovched into the sea, and furnished 

 it with the sedimentary material whose accumula- 

 tion to the thickness of nearly five hundred feet, 

 ultimately formed the Loudon clay. This laud was 

 clothed with a gorgeous and luxuriant flora, more 

 like that fringing the banks of the Indian rivers, or 

 the islands of the Malayan Archipelago, than any 

 elsewhere growing in the world. Principal among 

 the tropical forms were the palm-trees, whose 

 graceful leaves hung over the water, and were re- 

 flected in its rippling depths. The succulent fruits of 

 these palms fell in the stream in immense numbers, 

 sometimes literally covering the surface, and were 

 carried seawards. In some places where the clay 

 was forming, these fruits, now known as Nipadites, 

 accumulated to an extraordinary thickness, as in 

 the Isle of Sheppy, where no fewer than a dozen 

 species have been met with. You will see the 

 correctness of my inference that an Indian climate 

 and scenery existed in England during Eocene 

 times, by-and-by; but, meantime, I may say that 



the only places where palms now grow, whose fruit 

 nearest resembles these of the London clay, are 

 the Moluccas. Tree-ferns and fan-palms, also, were 

 not lacking in the brilliant landscape ; whilst 

 Aiwnas, or " custard - apples," gourds, melons, 

 &c, completed the list. The rivers which ran 

 through these thickets of tropical vegetation were 

 haunted by crocodiles and gavials, lying in wait to 

 seize the harmless Paheotheria which might come 

 to drink, or to bathe themselves in the stream, 

 after the fashion of their nearest living representa- 

 tives, the tapirs. Opossums swarmed in the forest, 

 and there is good evidence for believing that, to- 

 wards the close of the period I am describing, 

 monkeys were introduced in what were then 

 Euglisb. woods ! At dusk, large bats, not unlike 

 those of the Indian islands, made their appearance. 

 Many of the fish which lived in the rivers were 

 ganoids, that is to say, had bony-plated, enamelled 

 scales, like the Polypterus of the South African 

 rivers. The remains of these fishes and bats have 

 been found in some abundance near Woodbridge, 

 in Suffolk. Lazily lurking in the flowery brakes of 

 the forest were huge serpents, some of them as big 

 as the boa-constrictor, and possessing characters 

 now distributed among that class, the pythons, 

 colubers, &c. In the rivers, and also in the 

 adjacent seas, swam terrible water- snakes, of an 

 enormous size, and with vertically flattened tails, 

 the better to enable them to swim. 



As you would expect from such an association of 

 aquatic dangers, many of the land animals fell a 

 prey, and portions of their carcases were either 

 deposited in the river mud or carried out seawards. 

 Hence I can tell you something of them, and point 

 out a few leading peculiarities. Chief and com- 

 monest among them were the tapiroid animals, to 

 which I have already alluded. These harmless 

 creatures were lighter built than the modern tapir, 

 although, like that species, they had a short pro- 

 boscis. Their name of Pulaotherium, or " ancient 

 beast," is well deserved, as, with the exception of 

 the marsupials, or pouched animals, they are really 

 the oldest warm-blooded quadrupeds with which I 

 am acquainted. They were thick-skinned or " pachy- 

 dermatous " animals ; but, like many of the early 

 types, possessed characters which are now more 

 or less distributed among at least three different 

 groups. The modifications of the higher animals, 

 at the time I am treating on, were necessarily fewer 

 than at present, when such an enormous zoological 

 aud physiological " division of labour " has ended 

 in more marked specific specialization. Hence the 

 Palceothcria had characters which relate them to 

 the tapir, horse, and rhinoceros ! About half a score 

 different species lived together, their sizes ranging 

 from that of a decent horse to that of a pig. Closely 

 allied to this extinct creature was the Anoplo- 

 therium, or " harmless beast," as both its name and 



