398 Scientific Intelligence — Geology. 



onic forms and the earliest representatives of that class in the oldest 

 geological epochs; an analogy which is so close, that it involves 

 another most important priticiple, viz., that the order of succession 

 in time, of the geological types, agrees with the gradual changes 

 which the animals of our day undergo during their metamorphoses, 

 thus giving us another guide to the manifold relations which exist 

 among animals, allowing us to avail ourselves, for the purpose of 

 classification, of the facts derived from the development of the whole 

 animal kingdom in geological epochs, as well as the development of 

 individual species in our epoch. But to this most fruitful principle 

 I shall have hereafter an opportunity of again calling attention. — 

 Agassizon Lake Superior,^. 191. 



SCIENTIFIC INTELLIGENCE. 



GEOLOGY. 



1. First Geological Appearance of Coniferm. — Coniferse (Pine 

 family), remarkable for the apparently whorled arrangement of their 

 branches, and for their evergreen leaves ; in most cases they form 

 hard cones, but one has soft, berry-Hke fruit. The seeds are naked, 

 winged, resting on the scales. The leaves are peculiar, the nerves 

 not being spread, but often gathered into compact bundles. The 

 Coniferse existed at a very early geological epoch. This was the first 

 family that became numerous after the ferns. Their remains are 

 easily recognised under the microscope by the circular disks on their 

 wood cells. 



2. A Proof of the Correctness of the Glacial Theory. — Professor 

 Agassiz, before starting, showed us a rock at the south entrance of 

 the bay, which he considered a proof positive of the correctness of the 

 glacial theory. Its surface was a couple of hundred yards in extent, 

 sloping regularly north to the water's edge. The whole was polished 

 and scratched, except where disintegrated. The scratches had two 

 directions, the prevailing one north 10° to 30° west, the other north 

 55° west. The scratches on the outer or lake-side, seemed to have 

 a rather more westerly direction than the rest. Great numbers of 

 these striae could be traced below the water's edge, from which they 

 ascended in some places at an angle of 30° with the surface, showing, 

 as the Professor remarked, that they could not have been produced 

 by a floating body. The rock is granitic, with an astonishing 

 number of veins and injections of epidotic felspar, granite, and trap, 

 often crossing each other so as to form a complicated net-work. 

 Wherever exposed, it was ground down to an even surface. — Agassiz 

 on Lake Superior, p. 50. 



