SCIENCE-GOSSIP. 



157 



ON SOME COAL PLANTS 



By John Butterwortii. 



•HPHE counties of Lancashire and Yorkshire are 

 ■*• the fortunate possessors of a particular 

 seam of coal, forming one of the lower series, which 

 has contributed more towards our present knowledge 

 of the vegetable origin of the coal than any other 

 coal seam in the world. One particular feature of 

 this coal seam is, that a considerable bulk of the 

 plants that contributed to its formation were 

 calcified before bituminization had time to begin ; 

 thus they have been preserved in most perfect 

 condition, and reveal their internal structure as if 

 they were living ; of course, as may be expected, 

 there are many fragmentary portions of older 

 decayed plants surrounding the more perfect forms. 

 Having laboured in the investigation of coal 

 plants for thirty years, collecting my own material, 

 cutting and preparing my own sections, I begin to 

 appreciate the vast variety of plant remains that 

 make up our coal seams. From time to time I 

 propose to contribute some particulars of these 

 coal plants, but it will not be possible to give a 

 description of them in anything like systematic 

 order, because they are not met with in such order. 



Fig. 1. (30 Diameters ) 



Fig. i. is of a transverse section of a coal plant 

 that has excited very considerable interest from its 

 close resemblance to one class of the climbing 

 plants of the South American tropics, viz. : the 

 Bignoniacese. These climbing plants are well 

 known in the cotton districts of Lancashire, from 

 the fact that they reach this country as natural 



ropes by which bales of cotton from Brazil are 

 bound up. The prevailing form in this group of 

 climbers, viz., the Bignoniacese, is one in which the 

 woody and cortical systems assume a very sym- 

 metrical outline. 



In cutting sections of these climbing plants, if 

 the specimen is somewhat dry, the central or 

 woody system drops out and it locks very like a 

 Maltese cross. Fig. 2 is a photograph of a section 



Fig. 2. (8 Diameters.) 



that has behaved in this manner. It must be 

 understood, however, that this species of climber is 

 only compared with the fossil plant, fig. 1, because 

 of its close resemblance in form to the same. Like 

 many of our fossil plants, its physiological structure 

 is a puzzle. It has a vascular axis or pith, the 

 vessels of which carry spiral markings, while the 

 walls of the woody wedges are pierced with 

 reticulated openings. Its growth is exogenous, the 

 msdullary rays being clearly shown in a tangental 

 section of one of the woody wedges, and yet it 

 is believed to belong to the Cryptogams. In a very 

 young state it has a vascular axis surrounded by a 

 thick zone of cellular tissue and a very thin cortex. 

 The number of wedges in a full-grown plant seems 

 to number about six, this being the largest number 

 met with up to the present. These woody wedges 

 would appear to start growth from the medulla, or 

 pith, in single wedges; however, I have never seen 

 sections with less than two wedges, and I possess a 

 section having that number. I have seen others 



