OF CALAMITEAN STROBILUS. 263 



a highly developed Calamitean plant ; neither does any one 

 now doubt that the fruit of Calamites was cryptogamic. 

 Besides which^ we must remember that a cambium-layer 

 and an exogenous mode of growth are still found associated 

 with Cryptogamic inflorescence in all the living Marsile- 

 acese ; so that the possibility of the combination which I 

 have suggested is in strict accordance with conditions 

 known to exist_, instead of being, as some have supposed, 

 abnormal, and contradicted by all modern experience. 



The only other known Coal-measure plants in which re- 

 ticulated structures abound are those for which I have 

 proposed the name of Dictyoxylon"^. But whatever objec- 

 tions may suggest themselves to identifying the strobilus 

 with Calamopitus militate in a tenfold degree against a 

 similar identification with Dictyoxylon. The latter is not 

 only exogenous in growth, but probably a true Exogen 

 in the technical sense of the word, if not even an actual 

 Conifer; hence there is the greatest improbability that 

 it bore a Cryptogamic strobilus. But, on the other hand, 

 admitting that Calamopitus and this strobilus are equally 

 Calamitean in type, that they exhibit essential featui'cs 

 which they possess in common, and that in both cases 

 these features point to a higher organization than is usual 

 amongst the more ordinary Calamites, I am justified in 

 concluding that the subsistence of a close relationship be- 

 tween the two fossil plants is more than probable. As- 

 suming this probability to be established, what light does 

 the fact throw upon the affinities of the above fossils with 

 recent plants ? I find in my strobilus, as already stated, 

 nothing like Equisetiform elaters. The spores are simple 

 cells, which is also the case with recent Equisetiform spores 

 in their young state. But, for reasons already given, I 

 believe the fruit described to have been fully developed. 

 Consequently, so far as it goes, it gives no support to the 



* Monthly Microscopical Journal, No. viii. August, 1869. 



