4 



The Naturalist. 



to occupy a midway position between the Calamites and the ferns. 

 Ferns are among the most common fossils found in the whole coal 

 formation. They are well represented in the coal balls — the stems, 

 leaves, sporangia, and spores being frequently met with. The pines 

 are the next that I have to notice, one of which is called Dadoxylon. 

 The cast of the stem and its pith, which was formerly thought to be 

 a distinct species, and known as Sternhergia, is frequently met with 

 in our sandstone quarries. In the coal balls the whole stem is found 

 in a perfect state of preservation. A microscopic section cut from 

 one of these stems shows the annual rings of growth characteristic of 

 exogenous plants and the disk-bearing tissue which is present in all 

 known coniferse. The Dadoxylon was closely allied to the Araucarla, 

 or Norfolk island pine, and it grew to a great height. I have met 

 with them in our millstone grit rocks from one to two feet in 

 diameter. 



I now come to a most interesting class of fossils. In the coal balls 

 of Southowram we find a variety of seeds " of fruits called Gardio- 

 carpons ; one of them is about the size of a mustard-seed, and is 

 covered with small bracts. M. Brogniart and Professor Williamson 

 are just now investigating their structure ; the former gentleman has 

 described between 50 and 60 different kinds of them from the French 

 coal fields. My friend Mr. Binns has been fortunate in finding some 

 of these small fossils with spores in them. One small cone has the 

 sporangia, or bags containing spores, arranged in rows, in single file, 

 which appears to be closely allied to the Lepidostrobus jiemingites 

 alluded to by Professor Huxley as forming a large proportion of the 

 Lowmoor better bed coal. There is a very remarkable fact about these 

 sporangia, and that is, that the sporangia of the ancient gigantic 

 lepidodendrons are no larger than the sporangia of our small modern 

 clubmosses. The same holds good with the sporangia of the ancient 

 and modern ferns. It is very curious, also, that the sporangia of the 

 different species of ferns are all nearly of a size : for instance, those 

 of the humble wall- rue are as large as those of the giant AlsopJiila of 

 tropical regions. The sporangia of the horsetails of our ditches are 

 as large as those of their ancient representatives the Calamites, which 

 attained the height of from 20 to 30 feet. 



The foregoing remarks will show what an important bearing the 

 occurrence of these spore cases and spores in such a fine state of 

 preservation, have upon the history of these fossil plants, and also 

 the great importance of the study of these coal ball specimens, and 

 the interest which is attached to them by all our great fossil botanists. 



