VOYAGE FROM NEW YORK TO RIO DE JANEIRO. 43 



number of layers, all of wliich contain the remains of dis- 

 tinct populations. These different sets of inhabitants who 

 have possessed the earth at successive periods have each 

 a character of their own. The transmutation theory in- 

 sists that they owe their origin to gradual transformations, 

 and are not, therefore, the result of distinct creative acts. 

 All agree, however, that we arrive at a lower stratum where 

 no trace of life is to be found. Place it where we will : 

 suppose that we are mistaken in thinking that we have 

 reached the beginning of life with the lowest Cambrian 

 deposit ; suppose that the first animals preceded this epoch, 

 and that there was an earlier epoch, to be called the Lauren- 

 tian system, beside many others older still ; it is nevertheless 

 true that geology brings us down to a level at which the char- 

 acter of the earth's crust made organic life impossible. At 

 this point, wherever we place it, the origin of animals by de- 

 velopment was impossible, because they had no ancestors. 

 This is the true starting-point, and until we have some facts 

 to prove that the power, whatever it was, which originated 

 the first animals has ceased to act, I see no reason for refer- 

 ring the origin of life to any other cause. I grant that we 

 have no such evidence of an active creative power as Science 

 requires for positive demonstration of her laws, and that 

 we cannot explain the processes which lie at the origin of 

 life. But if the facts are insufficient on our side, they are 

 absolutely wanting on the other. We cannot certainly con- 

 sider the development theory proved, because a few natu- 

 ralists think it plausible : it seems plausible only to the 

 few, and it is demonstrated by none. I bring this subject 

 before you now, not to urge upon you this or that theory, 

 strong as my own convictions are. I wish only to warn 

 you, not against the development theory itself, but against 



