THE 



POPULAR SCIENCE 

 MONTHLY. 



JANUARY, 1877 



THE EARLIER FORMS OF LIFE. 



By Professor C. II. HITCHCOCK, 



STATE GEOLOGIST OF NEW HAMPSHIRE. 



rr^HE surmises and discoveries of the past twenty years have estab- 

 -J- lished the fact of the existence of life throughout the entire se- 

 ries of stratified rocks known to geologists, both sedimentary and 

 metamorphic. When Principal Dawson published his description of 

 the EozoOn in the Laurentian foundations, he was led to suggest the 

 adoption of the term Eozoic in place of Azoic for all the ages older 

 than Paleozoic, since, if life existed in the oldest formation, it must 

 have continued to flourish in the following seons, even though evi- 

 dences of its presence had not then been accumulated. Time has ap 

 proved of this sagacious anticipation, and we can now maintain with 

 serene confidence that the four great Eozoic periods Laurentian, 

 Labrador, Atlantic or Montalban, and Huronian were all enlivened 

 by the existence of both vegetable and animal life. And Eozoic life had 

 its peculiar characteristics just as much as the Silurian or Carboniferous. 

 This life has appeared in consonance with the general principles of 

 evolution as announced by our most learned sages. The earliest or- 

 ganic forms were the simplest in their structural relations ; and they 

 flourished through untold ages. The world was no longer young 

 when the organic scheme permitted the growth of Cambrian trilobites 

 and mollusca. More than half of geological time had passed away 

 during the reign of protozoans and fungi. This suggests the enun- 

 ciation of a general principle, in perfect agreement with the doctrines 

 of evolution : the simpler the predominating forms of life the longer 

 the period. In the beginning of Nature's operations, time was the 

 element of which lavish use was made. It has grown more valuable 

 as the ages ha,ve passed on, and the perfected type of organic develop- 

 ment in our period grudges the loss of a single moment of it. 



The evidences of the earlier forms of life naturally divide them- 

 VOL. x. 17 



