240 PHYSIOGRAPHY. [chap. 



about ^V^h ol an inch in diameter, and therefore readily 

 visible. These discs are the larger bodies cut through in 

 the section, and appear to be sacs which sometimes inclose 

 granules similar to those scattered through the dark ground- 

 mass, and which are not more perhaps than -j^ of an inch 

 in diameter. Botanists conclude that these minute bodies 

 are the spores} or reproductive bodies of a flowerless plant; 

 while Prof. Morris suggested, many years ago, that the larger 

 bodies are the cases which inclosed the spores and are 

 themselves known as sporangia. Similar bodies are well 

 seen in microscopic sections of the curious combustible 

 substance known as " white coal " which is in course of 

 formation in Australia. ^ 



There can be no doubt that these spores and spore- 

 cases were shed by trees closely related to those extinct 

 forms which are well-known under the r\a.xQQo{ Lepidodendron} 

 Remains of the lepidodendron have been found, with cones 

 still pendant from the branches of the tree ; and similar 

 cones, called Lepidostrobi, are scattered in abundance through 

 the coal-bearing rocks. The cones are made up of scales, 

 and in some specimens it is possible to detect spore-cases, 

 containing spores, still preserved between the scales. 

 Mr. Carruthers has given the name of F/eim'ngites to a lepi- 

 dodendroid plant which has been found to have spores, 

 closely resembling those which occur in the mass of the 

 coal. There seems therefore scarcely any room for doubt 

 that the little bodies so plentifully scattered through most 

 coals were derived from plants more or less resembling the 

 lepidodendron. 



1 Spores are one of the kinds of bodies by which flowerless plants are 

 reproduced. . 



^ Lepidodendron, from Xlins, lepis, a scale ; SeySpov, dendron, a tree ; 

 in allusion to the scale-like leaf-scars on the stems. 



