with broad marshes, over which the sea tides came and went for 
long distances, arose perhaps the first land plants. Here, 
through the centuries, they learned to crawl out of the sea and by 
degrees adapt themselves to a life on terra firma. Here perhaps 
began the ferns, horsetails, club-mosses, seed-bearing, cycad-like 
ferns, and the earliest relatives of the conifers. Speculation runs 
rife in this mysterious region, this nebula of the land-plant 
world. Some authorities believe our great land-plant flora de- 
veloped from types similar to our fresh-water scums and slimes 
through the liverwort; others equally authoritative suggest they 
arose as sparsely small-leaved tide-water plants from the numer- 
ous plant forms of the ancient seas. Be that as it may, one fact 
stands out clearly, viz., the presence of the two (or three?) great 
woody plant groups at the beginning of the coal period, and the 
absence of annual rings in their stems, denotes a land of perpet- 
ual summer, unmarred by seasonal changes. These two or three 
great groups are separated by very distinctive characters, such 
as the size of their leaves, the position of their fruiting bodies, 
and the nature of their internal anatomy. 
As one traces these groupsthrough the luxuriant but damp and 
gloomy forests of the coal period, one finds many strange trees. 
Giant club-mosses (Lepidodendrids, Sigillarians) with trunks 50 
to 100 feet high, clothed with long, spiny leaves or diamond-shaped 
leaf scars, compete with both low-growing and tree-like types of 
ferns, each exceedingly abundant. Tree-like horsetails ( Catamites) 
filled the swamps and their somewhat distant relatives, the 
Sphenophyllales , with curious foliage and slender, twining stems, 
were common. The cycad-like ferns, with “near-seeds, ” disputed 
the low grounds with the calamites, while the ancestors of the 
conifers ( Cordaita/es ) with long slender trunks surmounted by 
densely branched crowns with large leaves, occupied the higher 
ground. These magnificent though strange and gloomy forests 
of the coal age were not confined to America, but characterized 
the flora of the whole world, east, west, north and south , indicat- 
ing a climate much the same from Arctic to Antarctic. These 
queer forests from man’s standpoint were very uninviting, as 
they lacked those elements which to-day make them cheery — 
birds, flowers, and butterflies — although some rather objection- 
able inhabitants were present, such as cockroaches, frogs, scor- 
pions, and centipedes. Huge “snake-feeders,” or dragon flies, 
with wings over two feet in spread, flitted hither and thither over 
the calamite marshes, while pop-eyed, queer-shaped members of 
the frog and salamander groupmadethese alreadydark andgloomy 
swamps more hideous and uncanny with their croakings. 
The majority of our coal fields are the carbonized remains of 
these immense forest and swamp areas, conditions at that time 
being especially favorable for their preservation as coal. All the 
soft and cannel coals when properly treated, cut into thin sec- 
tions and subjectedto microscopic examination, show wood struc- 
ture, or, in the case of cannel coal, myriads of crushed pollen 
grains and spores with other swamp debris. 
At the close of the more or less tranquil coal period , the earth 
again became restless. Vast changes occurred. Mountain ranges 
arose (among them our own eastern mountains) . Enormous areas 
in the southern hemisphere, and to a lesser extent in the north- 
ern, were overrun by seas of ice. Europe and western North 
America, in part, dried up into deserts. 
Plant life, very naturally, was much affected by these various 
changes. The giant club-moss forests were doomed, and dis- 
appeared, only remnants existing in out-of-the-way places until 
the end of the Paleozoic era. The swamp-loving calamites were 
3 
