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THE POPULAR SCIENCE MONTHLY. 



I have already referred to it as a matter of considerable interest, 

 that a large proportion of some coal is made up of crushed vegetable 

 cells ; but that is not all a still more wonderful fact remains to be 

 noticed : The microscope, prying into all the little corners and secret 

 places.of Nature, declares that the pitchy parts of most bituminous coal 

 are composed almost entirely of little spherical bodies, microscopic in 

 size so minute, indeed, that hundreds of them together might well be 

 disregarded as " the small dust of the balance " and yet so numerous 

 that great coal-seams often appear to be made up of little else. Large 

 numbers of them are often found huddled together in small round sacs 



Fig. 8. Lepidodendeon compared with Clue-Moss : a. club-moss ; 6, a scale enlarged ; c. mi- 

 crospores ; d, macrospores ; x, lepidostrobus ; y and z, the ecales containing spores ; m, micro- 

 spores ; n. macrospores. 



of peculiar appearance. We are indebted to the patient labor of a 

 numb'er of observers for the fact that the smaller granules are the 

 spores or seeds of some plant of inferior organization, and the larger 

 sacs are fruit-cases in which the spores were developed. The whole 

 history of this fruit, the manner in which it was produced, its relation 

 to the stem and leaves of the plant to which it belongs, even its fertili- 

 zation and development, have all been carefully worked out w4th an 



