310 THE CANADIAN NATURALIST. [Jan. 



the previous specimens it was then observed to pass continuously 

 through two of the minerals, pyroxene and serpentine. Now we 

 have it imbedded in limestone, just as most fossils are. In every 

 case, with the exception of the Burgess specimens, the general form 

 is composed of carbonate of lime ; and we have good grounds for 

 supposing it was originally so in the Burgess specimens also. If, 

 therefore, with such evidence, and without the minute structure, I 

 was, upon a calculation of chances, disposed, in 1857, to look upon 

 the form as organic, much more must I so regard it when the 

 chances have been so much augmented by the subsequent accumu- 

 lation of evidence of the same kind, and the addition of the minute 

 structure, as described by Dr. Dawson, whose observations have 

 been confirmed and added to by the highest British authority 

 upon the class of animals to which the form has been referred, 

 leaving in my mind no room whatever for doubt of its organic 

 character. Objections to it as an organism have been made by 

 Professors King and Bowney ; but these appear to me to be based 

 upon the supposition that because some parts simulating organic 

 structure are undoubtedly mere miueral arrangement, therefore all 

 parts are mineral. Dr. Dawson has not proceeded upon the 

 opposite supposition, that because some parts are, in his opinion, 

 undoubtedly organic, therefore all parts stimulating organic 

 structure are organic ; but he has carefully distinguished between 

 the mineral and organic arrangements. I am aware, from having 

 supplied him with a vast number of specimens prepared for the 

 microscsope by the lapidary of the Canadian Survey, from a series 

 of rocks of Silurian and Huronian, as well as Laurentian age, and 

 from having followed the course of his investigation as it proceeded, 

 that nearly all the points of objection of Messrs. King and Bowney 

 passed in review before him prior to his coming to the conclusions 

 which he has published ; and his reply to these objections forms a 

 part of the succeeding paper. 



Ascending Section of the Laurentian Rocks in the County of 

 Eastings, Ontario. By Mr. H. G. Vennor. 



1. Reddish and flesh-coloured granitic gneiss, the thickness of Feet - 

 which is unknown ; estimated at not less than 2,000 



2. Greyish and flesh-coloured gneiss, sometimes hornblendic, 

 passing towards the summit into a dark mica-schist, and including 

 portions of greenish-white diorite ; mean of several pretty closely 

 agreeing measurements 10,400 



