CALAMAR1EAE. 3 O1 



medullary rays, which though formed most of them of only one row of 

 cells are still of some depth, are elongated in the direction of the axis of 

 the stem, as in the woods which we have been considering. These remains 

 are named Bornia enosti, Ren. Richter 1 had previously noticed these 

 fossils, but his account of them is not intelligible ; Goppert also had dis- 

 covered remains undoubtedly belonging to this plant in the Carboniferous 

 limestone of Glatzisch-Falkenberg, and his remarks upon them are of a 

 better kind ; his specimens 2 are it is true very fragmentary, but they show 

 single shallow medullary rays of one row of cells, and treatment of the 

 sections with acids also discloses tracheides with bordered pits broader than 

 long, and irregularly disposed in several rows. 



The rind is only rarely preserved in its connection with the wood, and 

 its structure appears from the statements of authors to be very variable. 

 The structure of the rind in the genus Astromyelon will be noticed again 

 presently. Renault 3 found that the rind of Arthropitys medullata was 

 composed of compact uniform parenchyma, and contained groups of 

 resin-canals (?) in front of the wedges of wood ; and that in A. bistriata 

 and A. lineata there was Dictyoxylon-structure also in the outer portion of 

 the rind, the well-known reticulated system of radial laterally anastomosing 

 strands of sclerenchyma. The only preparation before me in which the 

 rind is preserved, and which is from the Oldham nodules, presents to some^ 

 extent the conditions of the species first mentioned. A good specimen of 

 the kind is figured in Hick and Cash 4 ; it shows the soft bast which is 

 bounded on the outside by a layer of thick-walled cells. The primary rind 

 consists of an inner portion with delicate cells and with many fissures caused 

 by the tearing of the tissue, and of an outer layer, the elements of which have 

 thicker walls and frequently contain coal. Unfortunately no longitudinal 

 sections of this specimen have been published. 



In examining the wood in these plants it is not an uncommon thing to 

 come upon preparations which have struck the region of a node. I possess 

 such a preparation with the beginnings of four branches proceeding from the 

 node. The presence of the nodes can sometimes be recognised even from 

 without, if weathering or planes of fracture running in a favourable direction 

 have laid bare the outer surface of the wood stripped of the rind, or the 

 boundary line between it and the pith. Stur 5 , with a right perception of 

 the fact that it is only by attention to these points that we can have any 

 proof that certain casts of Calamitae belong to our woody bodies a proof, 

 on which rests the course of exposition here adopted has been careful to 

 collect all the cases of this kind known to him, and to discuss them fully. 

 His finest specimen 6 is represented in Fig. 40. It is a well-preserved 



1 Richter (1), p. 167. 2 Goppert (2), p. 100, tt. 38, 39. 3 Renault (15). 4 Hick 



and Cash (1), t. 19. 5 Stur (8). 6 Stur (8), p. 439. 



