374 THE CANADIAN NATURALIST. [Dec. 



and the plants to which it probably belongs, I have discussed in 

 the paper above mentioned. 



(2.) The coarser layers of coal show under the microscope a 

 confused mass of fragments of vegetable matter belonging to 

 various descriptions of plants, and including, but not usually 

 largely, sporangites, 



(3.) The more brilliant layers of the coal are seen, when 

 separated by thin laminae of clay, to have on their surfaces the 

 markings of Sigillariae and other trees, of which they evidently 

 represent flattened specimens, or rather the bark of such 

 specimens. Under the microscope, when their structures are 

 preserved, these layers show cortical tissues more abundantly than 

 any others. 



(-4.) Some tliin layers of coal consist mainly of flattened layers 

 of leaves of Cordaites or Pychnophjllum. 



(5.) The Stigmaria underclays and the stumps of Sigillaria in 

 the coal roofs equally testify to the accumulation of coal by the 

 growth of successive forests, more especially of Sigillarise. There 

 is on the other hand no necessary connection of sporangite beds 

 with Stigmarian soils. Such beds are more likely to be accumu- 

 lated in water, and consequently to constitute bituminous shales 

 and cannels. 



(6.) Lepidodendron and its allies, to which the spore-cases in 

 question appear to belong, are evidently much less important to 

 coal accumulation than Sigillaria, which cannot be affirmed to have 

 produced spore-cases similar to those in question, even though the 

 observation of Goldenberg as to their fruit can be relied on ; the 

 accuracy of which, however, I am inclined to doubt. 



On the whole then, while giving due credit to Prof. Huxley 

 and those who have preceded him in this matter, for directing 

 attention to this curious and no doubt important constituent of 

 mineral fuel, and admitting that I may possibly have given too 

 little attention to it, I must maintain that Sporangite beds are 

 exceptional among coals, and that, cortical and woody matters are 

 the most abundant ingredients in all the ordinary kinds ; and to 

 this I cannot think that the coals of England constitute an 

 exception. 



It is to be observed, in conclusion, that the spore-cases of plants, 

 in their indestructibility and richly carbonaceous character, only 

 partake of qualities common to most suberous and epidermal 

 matters, as I have explained in the publications already referred 



