206 THE STORY OF LIFE'S MECHANISM. 



parts. Whatever chemical forces may have 

 accomplished, they never could have combined 

 different bodies into linin, centrosomes, chromo- 

 somes, etc., which, as we have seen, are the basis 

 of cell life. To account for this machine, there- 

 fore, we are driven to assume either that it was 

 produced by some unknown intelligent power in 

 its present condition of complex adjustment, or 

 to assume that it has had a long history of build- 

 ing by successive steps, just as we have seen to 

 be the case with the higher organisms. The latter 

 assumption is, of course, in harmony with the 

 general trend of thought. To-day protoplasm is 

 produced only from other protoplasm ; but, plainly, 

 the first protoplasm on the earth must have had 

 a different origin. We must therefore next look 

 for facts which will enable us to understand its 

 origin. We have seen that the animal and plant 

 machines have been built up from the simple cell 

 as the result of its powers acting under the ordi- 

 nary conditions of nature. Now, in accordance 

 with this general line of thought, we shall be 

 compelled to assume that previous to the period 

 of building machinery which we have been con- 

 sidering, there was another period of machine 

 building, during which this cell machine was 

 built by certain natural forces. 



But here we are forced to stop, for nothing 

 which we yet know gives even a hint as to the 

 method by which this machine was produced. 

 We have, however, seen that there are forces in 

 nature efficient in building machines, as well as 

 those for producing chemical compounds; and 

 this, doubtless, suggests to us that there may be 



