180 THE STORY OF THE LIVING MACHINE. 



lution. It is made up of parts delicately adapted 

 to act in harmony with each other, and its activity 

 depends upon the relation of these parts. What- 

 ever chemical forces may have accomplished, 

 they never could have combined different bodies 

 into linin, centrosomes, chromosomes, etc., which, 

 as we have seen, are the basis of cell life. To 

 account for this machine, therefore, 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 building by suc- 

 cessive steps, just as we have seen to be the case 

 with the higher organisms. The latter assump- 

 tion 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 dif- 

 ferent 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 ordinary 

 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 considering, there 

 was another period of machine building during 

 which this cell machine was built by certain natu- 

 ral 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, 



