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NATURAL SCIENCE NEWS. 



ively represented by the ferns and 

 club mosses, the common mosses, 

 and lichens, fungi and seaweeds. 



Next let us see what relation 

 these primeval flora bears to that 

 of modern times. Two relations 

 are possible. First, that the prim- 

 eval flora may belong to a different 

 classification altogether; and sec- 

 ond, which is the true supposition, 

 that the whole flora of the earth, 

 from the earliest geologic times, 

 comes under one classification. 

 This shows that, from the begin- 

 ning of geologic time, one plan 

 has been followed out in the con- 

 struction of the vegetable king- 

 dom, and that the whole vegetable 

 kingdom consists not of the plants 

 now living on the earth, but in- 

 cludes all the plants that have ever 

 lived upon it. Again, there is an- 

 other possibility, that the primi- 

 tive flora may include representa- 

 tives of all our modern classes of 

 plants, or only some of them. The 

 fact is, that it includes mainly rep- 

 resentatives of some of them, and 

 those of a medium grade, neither 

 the lowest nor the highest, so far 

 as the land flora is concerned. 

 The fossil plants are not chiefly 

 exogens or endogens, but gymnos- 

 perms. On the other hand the 

 acrogens, or the highest group of 

 the cryptogamous plants in our 

 day were then the most abundant. 

 The primeval flora, therefore, em- 

 braced the higher cryptogams and 

 the lower phenogams. If we had 

 known nothing of vegetation but 

 that manifested by the primeval 

 flora we should not have known 

 the possibilities of the vegetable 

 kingdom, either in its highest 

 ranks or its lowest ranks, but only 

 in the middle of the scale. 



Next let us glance at the rela- 

 tions of the primeval flora to geo- 

 logic time. The oldest rocks we 

 know, the eozoic, have afforded no 

 plants, so far as we know, at all. 

 The next stratum, the paleozoic, 

 includes the oldest land plants we 

 know. But in the mesozoic peri- 

 od we arrive at a different flora, 

 and in the cainozoic, or modern 

 period, we have two other floras. 

 It is the paleozoic flora only of 

 which I shall speak tonight. Dur- 

 ing the whole of the paleozoic per- 

 iod, the seaweeds have existed. In 

 the earlier periods the classes of 

 acrogens and gymnosperms far ex- 

 ceeded the exogens and endogens, 

 while the reverse is the fact at the 

 present day. The warm and moist 

 climate of portions of the southern 

 hemisphere at the present day, 

 now have a flora more nearly re- 

 sembling the early epochs than any 



other portions of the earth. The 

 uniformity of the flora of that early 

 period indicates a temperature 

 nearly uniform throughout the 

 earth. At present we have in our 

 atmosphere but a small quantity 

 of carbonic acid gas. If we had 

 more it would tend to make lhe 

 climate more uniform, by prevent- 

 ing the radiation of heat from the 

 earth. The carbon locked up in 

 our coal mines, and then existing 

 in the atmosphere, may therefore 

 have been at least one reason for 

 the uniformity of climate on the 

 earth in the paleozoic period, the 

 flora of that day indicating a warm 

 and moist climate. 



Next, looking to the flora of the 

 plants, we will turn to the carbon- 

 iferous period, when there was a 

 vast amount of vegetation, after- 

 ward made fossil and becoming 

 coal. In that moist, warm, but 

 unwholesome atmosphere, we find 

 the sigillaria, or seal-tree, one of 

 those most abundant in the swamps 

 of the carbeniferous period. Here 

 we have a large tall stalk, without 

 branches, covered with large 

 leaves; or perhaps divided into a 

 few branches. We have remains 

 showing the ribbed structure of 

 the stalk, and the scars of the 

 leaves. There are no trees in our 

 latitude resembling it in structure. 

 We know of the fruit of the sigil- 

 laria only by the abundance of a 

 certain nut that is found around 

 them. Trees of two and three feet 

 in diameter were not uncommon. 

 The root of this tree is more re- 

 markable even than its stem, hav- 

 ing attracted the attention of geol- 

 ogists before the stem, and obtain- 

 ed the name of stigmaria. These 

 roots are bifurcated and spread 

 out in a remarkably regular way, 

 all the little rootlets spreading as 

 regularly as leaves. These roots 

 occur very often in the coal forma- 

 tion without the stems; and at first 

 it was supposed that they were 

 the whole of the plant. The first 

 process in the formation of a bed 

 of coal was usually the growth of 

 a forest of sigillaria. 



The next class are the calamites. 

 The lecturer here related an anec- 

 dote of an unlearned individual 

 who having been shown some 

 specimens of ferns and calamites, 

 the former being called filices, re- 

 ported to his friends that he had 

 seen the savant's "felicities" and 

 "calamities." In one sense the 

 calamites may be justly styled cal- 

 amities, for they had been the sub- 

 ject of more dispute on the part of 

 geologists perhaps than any other 

 fossil plant. They seem to have 







grown on muddy flats along the 

 margin of the sigillarian woods, 

 resembling equiseta or mare's tails; 

 and they are still preserved in coal 

 formations in large numbers. The 

 calamites seem to have preserved 

 the sigillarian forests from the ef- 

 fects of inundation, by causing the 

 mud to settle before the waters 

 passed into the forests. The cal- 

 amites thus contributed very much 

 to the purity of our coal beds. 



The next plant is the lepidoden- 

 dron or scale-tree, of a size equal 

 to the sigillaria, resembling our 

 ground pines or club-mosses. This 

 tree was more plentiful in the ear- 

 lier coal formations than in later 

 periods. Many other diagrams 

 and petrifactions of fossil plants 

 were here exhibited. The plants 

 of the carboniferous period would 

 have presented to our eyes a .very 

 monotonous appearance; for it was 

 characteristic of the flora of that 

 period that there was a large num- 

 ber of species, but few genera. 

 There were also some plants more 

 familiar to our eyes. The ferns 

 are to be found in the coal beds 

 preserved as beautifully as they 

 could have been preserved in an 

 herbarium. They resembled more 

 closely the ferns of New Zealand 

 or the Hebrides than the ferns with 

 which we are familiar. Some of 

 these ferns grew to the dignity and 

 beauty of the palm-tree itself. 

 One species was peculiar, having 

 only two leaves at a time. We 

 find sometimes in the coal-beds 

 things looking like enormous 

 brooms, which are tree-ferns, with 

 roots sent out to straighten the 

 stems. 



We also find in the coal forma- 

 tion varities of pine, the wood of 

 which much resembled our mod- 

 ern pines. It is remarkable "that 

 the pine is widely diffused at the 

 present day; and it is not wonder- 

 ful, therefore, that they should 

 have existed in the carboniferous 

 period. These pines have features I 

 more nearly resembling those of 

 Australia and New Zealand than I 

 those of our climate. When wood I 

 is buried in the earth and its cells j] 

 filled wfth stone, and the wood be- 

 comes coal; and this is the form in 

 which we find these fossil remains. 

 By removing the mineral we can I 

 observe the vegetable structure of 

 the plants, and determine their ![ 

 character. Next to the soil on 

 which we tread, the most valuable ; ; 

 substance we have is mineral coal, I 

 which is derived from the plants 1 

 of the carboniferous period. A j- 

 bed of coal is usually composed of 

 the remains of the trunk and bark ; 



