OF CALAMITEAN STROBILUS. 259 



inclined to believe tliat the dark central portions seen in 

 fig. 12 were the spores, enclosed within a true cell; but 

 after a very careful conjoint examination made by Mr. Car- 

 ruthers and myself, we satisfied ourselves that each cell in 

 its entirety constituted a separate spore. They have an 

 average diameter of from 2^-^ to -3-^ of an inch, whilst the 

 dark central mass is from 3-^ to ^^^-(j of an inch. 



As a rule, I distrust most detailed restorations of fossil 

 plants; but in this instance the specimen is in such 

 exquisite preservation that there can be no doubt as 

 to the general plan of its construction. Fig. 13 may 

 be regarded as a vertical section of its five lower seg- 

 ments, of which the sporangia are supplied to two of the 

 lower ones, whilst the upper two show the relations of the 

 axis to the bractigerous disk and its appendages. That the 

 pith has been fistular in the fully developed cone I infer 

 from the beautiful preservation and sharply defined outline 

 of the cellular tissue lining the interior of the woody axis, 

 combined with the presence, within the cavity, of perfect 

 rootlets of Stigmaria, the latter especially proving that the 

 axis was hollow when the strobilus fell into the mud which 

 the SHgmaria-YOots were permeating with their ubiquitous 

 fibres. 



We have next to consider the probable relations of this 

 strobilus to other Coal-measure plants, and especially to 

 the somewhat similar structures described by Mr. Binney^ 

 and Mr. Carruthersf, the specimens studied by the latter 

 gentleman having been also derived from Mr. Binney^s 

 collection, and being identical in nature with those figured 

 by him. In all essential features my plant corresponds with 

 these, as well as with that described by M. Ludwig and 

 referred to by Mr. Carruthers in the above memoir. Mr. 



* Loc. cit. 



t "On the Structure of the Fruit of Calamites," by Wm. Carruthers, 

 Esq., F.L.S., Journal of Botany, Dec. 1867. 



S2 



