INTRODUCTORY. O 



chain o being that produced all the population of the 

 world. Independently of any such hypotheses, all 

 students of nature must regard with surpassing in- 

 terest the first bright streaks of light that break on 

 the long reign of primeval night and death, and pre- 

 sage the busy day of teeming animal existence. 



No wonder then that geologists have long and 

 earnestly groped in the rocky archives of the earth in 

 search of some record of this patriarch of the animal 

 kingdom. But after long and patient research, there 

 still remained a large residuum of the oldest rocks, 

 destitute of all traces of living beings, and designated 

 by the hopeless name " Azoic/' the formations desti- 

 tute of remains of life, the stony records of a lifeless 

 world. So the matter remained till the Laurentian 

 rocks of Canada, lying at the base of these old Azoic 

 formations, afforded forms believed to be of organic 

 origin. The discovery was hailed with enthusiasm by 

 those who had been prepared by previous study to re- 

 ceive it. It was regarded with feeble and not very 

 intelligent faith by many more, and was met with 

 half-concealed or open scepticism by others. It pro- 

 duced a copious crop of descriptive and controversial 

 literature, but for the most part technical, and con- 

 fined to scientific transactions and periodicals, read by 

 very few except specialists. Thus, few even of geo- 

 logical and biological students have clear ideas of the 

 real nature and mode of occurrence of these ancient 

 organisms, and of their relations to better known 

 forms of life ; while the crudest and most inaccurate 



