554 Transactions of the Canadian Institute. [Vol. VII. 



portions, on the other.* In consequence, their descendant forms 

 inherited this relation, and transmitted it to the forms and species which 

 arose through variation and other causes. When multicellular forms 

 arose these were endowed with the same relation. 



The proportions of the elements in the early pre-Cambrian ocean 

 with their long action on protoplasm must then have conferred a more 

 or less fixed property on the latter and, in consequence, living matter, 

 whether animal or vegetable, now shows in its ash proportions of the 

 elements greatly different from those found in the media in which it 

 lives or in the circulatory fluid which bathes it. This relation or 

 property resists change even after exposure to altered conditions for a 

 very long period of time. Before the circulatory fluid (blood plasma) 

 was established in multicellular animals, a great change must have 

 occurred in the proportions of the elements in the ocean, a change which 

 would account for the wide differences between the proportions in the 

 protoplasm or tissue on the one hand, and those in the blood on the 

 other. 



The proportions of the elements in living matter are due then to 

 conditions which obtained in the ocean far back in the pre-Cambrian age, 

 while those in the blood or plasma are due to conditions which occurred 

 in the ocean long after this and yet before the beginning of the Cam- 

 brian period. The proportion of potassium to sodium in blood plasma is 

 nearlyf double what it is in the ocean and therefore that difference must 

 have resulted in the period that has elapsed since the rudiments of a 

 circulatory system were developed in those Metazoan animals which 

 gave rise to Vertebrates. 



As pointed out above, it is difficult to obtain the exact proportions 

 of the sodium, potassium, calcium and magnesium in living matter, for, 

 except in muscle fibre, protoplasmic structures cannot in sufficient 

 quantities be freed from adherent material which carries these elements 

 in very different proportions. Calcium exists in tissues apart from the 

 protoplasm and as precipitates or deposits, and according to recent 

 observations which I have made, this is true in a very large degree of 



* Geologists concede a very long time to the pre-Cambrian, a duration which, according to the different 

 estimates, ranges from one-third to tour-fifths, and even nine-tenths, of the whole geological period. The 

 very fact that all the chief types of animal lite, and perhaps also of vegetable life as well, appeared before the 

 close of the pre-Cambrian age, indicated that the latter was of inconceivably long duration. 



t Amongst the oldest and highly specialized forms are Olenellus and the Brachiopods of the Cambrian. 

 The oldest Vertebrate remains are in the Trenton division of the Silurian, more recent than the Cambrian, 

 but these are " ganoid" in character and this fact postulates a long preceding period of development out ot 

 Protovertebrate forms which therefore could not have first appeared much later than the beginning of the 

 Cambrian. The circulatory system of Vertebrates accordingly has a history which began in the pre- 

 Cambrian age. 



