7-1 



HARDWICKE'S SCIENCE-GOSSIP. 



tioued, and is by far the thickest member of the 

 group. 



The dry land of this period was broken into a 

 series of undulations, as it is at present, although 

 the mountains were not so high as they are now. 

 The uplands were thickly covered with woods and 

 forests of Araucarian pines and thickets of fern ; 

 whilst the lowlands were green with densely-packed 

 cycads, plants now confined to tropical regions. 

 About one hundred species of Lias plants are 

 known to science, but not one has yet been met 

 with which belonged to the class of which the oak, 

 ash, or nettle are familiar examples. Indeed, this 

 group was not introduced until the Cretaceous 

 epoch, which followed the Liassic after the lapse of 

 enormous periods of time. The ferns were remark- 

 able for having reticulated veins traversing their 

 fronds. In the damper places, and by the river- 

 sides, there grew miniature forests of equisetum, 

 nearly allied to existing species. This was almost 

 the only " English " feature about the Liassic land- 

 scape. The trees grew in many places on the low- 

 lands by the sea, and the dark mud was often 

 charged with the resin lumps, which, under the 

 name of "jet," now compose my personal substance. 

 Amid this somewhat monotonous vegetation there 

 lived several species of miniature marsupials — the 

 only warm-blooded creatures then in existence — 

 which found the chief means of their subsistence in 

 the hosts of insects which peopled grove and plain. 

 Land reptiles, also, were not absent, both as croco- 

 diles, tree-lizards, and flying-lizards. 



This was, indeed, " the Age of Reptiles." Rep- 

 tilian life was then modified to the various functions 

 now fulfilled by a higher class— the Mammalia. 

 In the air, on the land, in the water, one met witli 

 reptilian adaptations at every step. The places now 

 filled by the whales and seals were then occupied by 

 the Ichthyosaurus and the Plesiosaurus. The great 

 land reptiles (Deinosauria) , which became so abundant 

 during the later — I may say the continuing " Oolite " 

 period — stood in the room of modern carnivora and 

 herbivora. Instead of bats and birds winging their 

 way through the air, there were groups of Ptero- 

 dactyles, some of them as large as the greatest bird 

 now living. And, just as there is a certain me- 

 chanical and anatomical arrangement now charac- 

 terizing the specialized mammalia, and thus fitting 

 them for their various functions and places, so 

 during the " Age of Reptiles " the relatively lower 

 forms were built on the same plan. The modifica- 

 tion which converts the limbs of a whale into fins, 

 also converted those of the Ichthyosaurus into 

 paddles ; the adaptation which provides a fulcrum 

 for the muscles of a bird by fusing two or more 

 bones together, we find applied to the flying-lizards 

 of the Lias period. So wonderfully simple is the 

 great plan on which the Creator has chosen always 

 to govern the development of organic beings. 



Sometimes the lumps of resin which had oozed 

 out of the pine-trees floated seawards, and were 

 afterwards buried in the muds along the bottom . 

 At others, the marsh lauds where the woods grew 

 were encroached on by the sea, and from terrestrial 

 passed to marine conditions. It was whilst I lay 

 thus that I formed my vivid impressions of the 

 strange creatures which swam above me, and whose 

 deceased bodies occasionally sank down into the 

 mud to rest by my side, until I was rescued, in my 

 mineral condition as "jet," by that complex and 

 greedy being called " Man " ! I will endeavour to 

 recall the most remarkable of these creatures. Eirst 

 there was the Ichthyosaurus, or rather, several 

 species of that reptile : as its name implies ("fish- 

 lizard "), it was modified to a purely marine life ; 

 which its deeply double convex vertebrae also indi- 

 cate. Some of the larger individuals attained a 

 length of thirty feet, and I remember them going 

 through all the usual routine of their reptilian life 

 in the waters along whose floor I lay and watched. 

 They were carnivorous in their habits, feeding on the 

 larger fishes, and even on one another. To the best 

 of my belief they differed from most reptiles in bring- 

 ing forth their young alive. Many a lime have I 

 seen one of their carcases floating by means of the 

 decomposed gases right over where I lay ; by-and- 

 by the gases would escape, and the body sink to 

 the muddy bottom ; there it lay and was mineral- 

 ized, and thence the geologist now disinters it iu 

 long ages subsequent to the elevation of this sea- 

 bed into dry land. And his researches bear out the 

 truth of what I say, for he frequently finds the fos- 

 silized remains of the reptile's last meal enclosed 

 within the ribs where the stomach once lay, and 

 even the fossil f octal remains of its young within the 

 pelvic cavities. The Ichthyosaurus was indeed the 

 tyrant of the Liassic seas ; its crocodile-like head 

 was armed with scores of conical teeth, implanted 

 in a continuous groove ; the rest of its body was not 

 unlike that of a small whale, having similar paddles 

 and tail. 



Still more nearly related to the Lizard family (as 

 its name implies) was the Plesiosaurus, whose 

 habits, however, were quite different from its more 

 tyrannical congener. Its head was much smaller, 

 although thoroughly reptilian, and terminated a long 

 neck, not unlike that of the swan, or even longer, 

 for it sometimes contained as many as forty 

 vertebrae : its teeth were implanted in sockets, like 

 those of the modern crocodile, so that, with a neck 

 resembling a snake, a body and tail like those of a 

 quadruped, and having paddles like the turtle, the 

 Plesiosaurus had combined in itself structural adap- 

 tations now distributed among half a dozen widely 

 separated animals. The largest of these queer- 

 looking reptiles was twenty feet in length. Usually, 

 its locality was by the seashore, in the shallower 

 waters, where, by the aid ,of its long and flexible 



