HARDWICKE'S SCIENCE-GOSSIP. 



29 



ranked among the beautiful, yet it compensates for 

 this by its rarity and venerable age. 

 t> It has lain in my cabinet for some years, in the hope 

 that I might make further discoveries from the same 

 source, but after many long searches and subsequent 

 labour in preparing the material I have never done 

 more than verify the typical slide I am about to 

 describe. That it is the type of the prevailing 

 vegetation of the period I have no doubt, as I have 

 frequently found traces of the same structure, but 

 always in such a bad state of preservation that without 

 the knowledge obtained from this identical slide it 

 would have been difficult to make out its detail at all. 



have been absent. I have found the same occur in 

 sections of Sigillaria from our coal measures, and this 

 induces me to think this fragment received its greatest 

 pressure at this point, and thus comparatively relieved 

 the immediately surrounding parts from the pressure 

 necessary to destroy structure. 



It appears to consist entirely of a vast number of 

 simple tubular cells, having a very thick wall which 

 by its slightly darker colour clearly defines the 

 boundary of each. They are mostly exhibited as 

 cut obliquely transverse, but the few that are dis- 

 covered having a longitudinal section measure about 

 •^ of an inch in length, by ^ in breadth, they 

 terminate abruptly, and appear to be separated from 

 the succeeding cell by an exceedingly thin division, 

 similar to some of the freshwater Algae. As an 

 example I would mention Phyllactidium pulchdlum. 

 Each tube or cell appears to have been connected 

 with the succeeding one at the end only, as no indi- 



',4^:=- 



•^ 



Description. — The piece of fossil vegetable, as 

 mounted, measures two tenths of an inch long by 

 just one-tenth in its widest part ; it is somewhat 

 angular in shape, and, for the reasons presently to be 

 stated, appears to be an almost transverse section of 

 the original plant. In colour it resembles a piece of 

 seasoned oak. It was exceedingly friable and is 

 traversed by many fine fractures. The preservative 

 material has doubtless been protoxide of iron, but I 

 cannot help thinking the perfect preservation of the 

 structure has been in a great measure due to acci- 

 dental protection from the great pressure these plants 

 must have suffered, as in one part a perfectly structure- 

 less portion appears, although from the size of the cells 

 and the general surroundings, the structure should not 



cation of branching is discernible either in the longi- 

 tudinal or transverse tubes. 



Occasionally some of the cells or tubes contain some 

 dark coloured spherical bodies, uniform in size, and 

 apparently arranged in a double row. I have counted 

 twenty in a cell ^gj,, by ^^-^-y Sections of these botlies 

 are seen in other cells, but their minuteness defies 

 the limit of my instrument to detect structure in any. 

 I look upon these as being the germs of future plants, 

 had not mineralisation interfered with their develop- 

 ment. 



In Pachythcca spha/'ica we have a much more 

 complicated structure, but still bearing a strong 

 resemblance to that of the plant above described. 

 The tubular structure is exhibited here, with the same 

 absence of constriction at the ends of the cells, Init 

 instead of being connected simply with each other by 

 their ends they branch off at right angles in all 

 directions, leaving small interstices between. 



Towards the boundary of the sphere these tubes 

 become compacted closer together, and probably gave 

 a tolerable degree of solidity to the organism. Rami- 



