50 THE GEOLOGICAL HISTORY OF PLANTS. 



sequent chapter, these curious little bodies were again 

 reviewed, and were described in substance as follows : 



" The oldest bed of spore-cases known to me is that 

 at Kettle Point, Lake Huron. It is a bed of brown 

 bituminous shale, burning with much flame, and under 

 a lens is seen to be studded with flattened disc-like bodies, 

 scarcely more than a hundredth of an inch in diameter, 

 which under the microscope are found to be spore-cases 

 (or macrospores) slightly papillate externally (or more 

 properly marked with dark pores), and sometimes show- 

 ing a point of attachment on one side and a slit more or 

 less elongated and gaping on the other. When slices of 

 the rock are made, its substance is seen to be filled with 

 these bodies, which, yiewed as transparent objects, appear 

 yellow like amber, and show little structure, except that 

 the walls can be distinguished from the internal cavity, 

 which may sometimes be seen to enclose patches of granu- 

 lar matter. In the shale containing them are also vast 

 numbers of rounded, translucent granules, which may be 

 escaped spores (microspores)." The bed containing these 

 spores at Kettle Point was stated, in the reports of the 

 "Geological Survey of Canada," to be twelve or fourteen 

 feet in thickness, and besides these specimens it contained 

 fossil plants referable to the species Calamites inornatus 

 and Lepidodendron primmvum, and I not unnaturally 

 supposed that the Sporangites might be the fruit of the 

 latter plant. I also noticed their resemblance to the 

 spore-cases of L. corrugatum of the Lower Carboniferous 

 (a Lepidodendron allied to L. primcevum), and to those 

 from Brazil described by Carruthers under the name 

 Flemingites, as well as to those described by Huxley 

 from certain English coals, and to those of the Tasmanite 

 or white coal of Australia. The bed at Kettle Point is 

 shown to be marine by its holding the sea-weed known 

 as Spirophyton, and shells of Lingula. 



The subject did not again come under my notice till 



