HARDWICKE'S SCIENCE-GOSSIP. 



[Jan. 1, 1S69. 



the slowly ebbing and flowing tides bad access 

 nearly twice a day. Around the more aged trunks 

 of these extinct trees, standing on a muddy, 

 shallow sea-bottom, so to speak — marine worms 

 clustered, and their coiled tubes are now occasionally 

 found fossilized, along with the petrified vegetation 

 to which they clung when in life. These Spirorbi, 

 as they are commonly termed, are tolerably plentiful 

 in the north of England. It was owing to the 

 semi-marine, semi-terrestrial character of the area on 

 which the luxuriant vegetation of the Carboniferous 

 period grew, that we now find so many fossil 

 mussels and other marine shells imbedded in the 

 same strata. 



I am told that chemists nowadays have dis- 

 covered only one atom or particle of carbon asso- 

 ciated with every thousand of the other gases 

 forming the atmosphere. The atmosphere of the 

 period when I was born hardly contained more. 

 This small quantum was absorbed by the waving 

 forests into their structure, and thus added to their 

 solid bulk. Day by day, and year by year, each 

 individual tree grew, so that the mass of solidified 

 carbon increased, but without exhausting the 

 original store. This was constantly being furnished 

 by volcanoes, as well as by the lowly animals of my 

 own time. Everything, they say, is composed of 

 minute and cellular parts, and originally my atoms 

 freely floated in the air as so many particles of 

 carbon. This was before I had entered into that 

 combination which made me part and parcel of a 

 living tree. Once having been sucked into the leaf- 

 pores of a Lepidodendron or Sigillaria, I started 

 existence under a new form. I became subject to 

 those unknown laws of vital force which philoso- 

 phers find so great a difficulty in explaining. I had 

 now an active duty to perform, and had to assist in 

 the growth and well-being of the tree in whose 

 bulk I lay. But this did not prevent me from 

 noticing the many strange objects which surrounded 

 me. Human beings there were none, nor did the 

 race to which I am now so useful an auxiliary 

 appear upon the earth's platform for millions of 

 years afterwards. Tree lizards, not very much 

 larger than those which haunt the sunny banks of 

 old England, climbed up and down the sculptured 

 branches of the forest trees, and lived upon the 

 marsh flics and beetles, whose " drowsy hum " was 

 the only sound that broke upon the stillness of 

 these primeval woods. They found a shelter in the 

 hollow trunks of Sigillaria', in association with the 

 pupa; of beetles and other insects. In some places 

 they have been found fossilized together, — a con- 

 served recollection of those bygone times. Great 

 reptiles, much resembling a frog, only as large as a 

 small ox, waddled to and fro over the extensive 

 beaches, and left their enormous hand-like impres- 

 sions in myriads upon the yielding mud. As such 

 they are now found in the flaggy sandstones which 



compose the strata of the coal formation. Occa- 

 sionally, when overtaken by death, their carcases 

 rotted on the shores, and were imbedded in the 

 sands, to be found in long- subsequent ages in a fossil 

 state. Several species of these gigantic batrachians 

 existed contemporaneously. Very frequently the,salt- 

 water reaches were visited by alligator-like animals, 

 now termed Archtegosaurus, whose bodies were 

 covered by hard, horny scutes or scales, held to- 

 gether much after the manner a slater now adopts 

 when he tiles a house. These reptiles were five and 

 six feet long, and, together with the great frogs I 

 have mentioned, were the principal and most power- 

 ful animals of the age I am speaking of. The 

 atmosphere differed little from its present condition, 

 being neither denser nor more rarified. This you 

 may prove for yourself by the impressions of rain- 

 drops preserved in the Carboniferous sandstones. 

 The great drops were driven by the wind aslant, so 

 that even now there is indicated the very quarter 

 from which the wind blew at the time ! The passing 

 shower over, the sun peeped forth from behind the 

 dark clouds, and his heat baked the mud, and 

 cracked it, just as he does now the bottom of a 

 clayey pond. These sun-cracks were subsequently 

 filled up, sometimes by sand of a different colour, so 

 that they are fossilized as truly as the shells and 

 plants. The same sandstones yet bear the trail- 

 markings which the marine worms left after they 

 had crawled over them when in a soft state. Occa- 

 sionally you may even come across their burrows or 

 holes ; whilst the flagstones also are impressed with 

 ripple-marks left by the retreating tides ! 



Although the sea-bottom was so shallow in the 

 neighbourhood of the great forests, I should state that 

 many miles further out it gradually shelved deeper, 

 until there was an area where " blue water " was at- 

 tained. Here the sea was fairly alive with animals of 

 all sorts of natural liistory orders and classes. Coral 

 banks, with animals putting forth their beautifully 

 coloured tentacles, more various than the rainbow 

 hues, stretched over many leagues of old Devonian 

 rocks, and, as the area was slowly submerging at 

 the time, their united labours, in the course of ages, 

 produced no small portion of what is now termed 

 the "Mountain Limestone." Shell-fish, allied to 

 the existing nautilus, found in these purer waters, 

 free from land sediment, the essentials of their well- 

 being. In the limestones which their dead shells 

 helped to form there are no fewer than thirty 

 different species of nautilus ! They had relatives 

 termed Goniatites (long since died out, for they did 

 not possess the hardiness of their congeners), whose 

 chambers were fashioned in a zigzag or angular 

 manner. Then came another group of shell-fish, 

 equally near by blood, the Gyroceras, whose coils did 

 not lie so closely together', as those of the nautdus. 

 One other class of cephalopods are now known as 

 Orthoceratites. They were also chambered, but 



