Carboniferous Coal Age. 83 



diameter. It has been doubted if it belongs with the Equiseta, which, 

 in the tropics, now grow thirty feet high but very slender. The an- 

 cient calami te had whorls of scale-like or thread-like leaves at the joints, 

 which, however, the Equiseta have also. Yet from their size and their 

 appearance of having exogenous woody tissue, LeConte proposes to 

 class them as a cross or connecting link between the Equiseta and 

 Conifers. 



The Lepidodendron (scale tree) grew to the height of forty to sixty 

 feet, with wide spreading roots. The surface of the trunk and branches 

 was scarred or marked all over in rhomboidal patterns and covered with 

 scale-like or spine-like or needle-like leaves, the branches terminating in 

 a club-shaped extremity, like the club mosses. And like the club 

 mosses, too, they propagated by double spores the microspore and the 

 macrospore answering to stamens and pistils. They are classed as 

 Lycopods, with some characteristics of Conifers. 



The Sigillaria was sometimes sixty to one hundred feet tall, gradually 

 tapering, and fluted vertically, like a Corinthian column. It had wide 

 spreading roots for the soft ground where it grew. In the flutings were 

 series of seal-like impressions on the bark. These trees are related to 

 the Lepidodendrids on the one side, and have also characteristics of the 

 Cycads, which made their appearance in the Triassic. 



In addition to these there are logs, stumps, fruit and leaves of trees 

 that are classed as belonging to Conifers. Some of them resemble 

 tropical Conifers of the present time. ' ' Their nearest living congeners 

 seem to be among the tropical family Araucariae ( Norfolk Island pine), 

 or among the broad-leaved Conifers, like the Salisburia of China and 

 the curious Welwitschia of South Africa. This last anomalous Conifer, 

 with a trunk three or four feet in diameter and only one foot high, bears 

 but two strap-shaped leaves, ( the original cotyledons ) of great size 

 (two or three feet wide and six feet long ), which last during its whole 

 life of 100 years. " Other forms are equally odd. These descriptions 

 are of representative forms. The whole number of species is over a 

 thousand in America and Europe, of which about one hundred and 

 fifty are common to both continents. In this list there are no Angio- 

 sperms, such as the maple, elm, apple, &c. , and no Endogens grasses, 

 cereals; reeds, palms, &c. The appearance of these more highly organ- 

 ized plants occurs much later, viz., in the Cretaceous period. A few 

 mushrooms appear. 



As to animal life there is the same general changing of genera and 

 species among the mollusks, corals and crinoids. But there are some 

 quite important innovations. Dry land led to new possibilities, and we 

 now have forms impossible before. Among the Articulates ( Arthro- 

 ~*^Le Conte 347. ~" 



