WHAT MAY BE LEARNED FROM EOZOON 165 



can it predict anything as to the order or manner of their 

 introduction. 



Had we been permitted to visit the Laurentian seas, and to 

 study Eozoon and its contemporary Protozoa when alive, it is 

 plain that we could not have foreseen or predicted from the 

 consideration of such organisms the future development of life. 

 No amount of study of the prototypal Foraminifer could have 

 led us distinctly to the conception of even a Sponge or a Polyp, 

 much less of any of the higher animals. Why is this ? The 

 answer is that the improvement into such higher types does not 

 take place by any change of the elementary sarcode, either in 

 those chemical, mechanical, or vital properties which we can 

 study, but in the adding to it of new structures. In the Sponge, 

 which is perhaps the nearest type of all, we have the movable 

 pulsating cilium and true animal cellular tissue, and along with 

 this the spicular or fibrous skeleton, these structures leading to 

 an entire change in the mode of life and subsistence. In the 

 higher types of animals it is the same. Even in the highest we 

 have white blood corpuscles and germinal matter, which, in so 

 far as we know, carry on no higher forms of life than those of an 

 Amoeba ; but they are now made subordinate to other kinds of 

 tissues, of great variety and complexity, which never have been 

 observed to arise out of the growth of any Protozoon. There 

 would be only a few conceivable inferences which the highest 

 finite intelligence could deduce as to the development of future 

 and higher animals. He might infer that the Foraminiferal 

 sarcode, once introduced, might be the substratum or founda- 

 tion of other but unknown tissues in the higher animals, and 

 that the Protozoon type might continue to subsist side by side 

 with higher forms of living things, as they were successively 

 introduced. He might also infer that the elevation of the 

 animal kingdom would take place with reference to those new 

 properties of sensation and voluntary motion in which the 

 humblest animals diverge from the life of the plant 



