4 EVOLUTIONS OF ORGANIZATION. 



with the phenomena of life, and learns the me- 

 chanical and chemical processes involved in them, 

 he naturally asks how far the laws of life are to 

 be explained by the laws of matter, and what is 

 the motive power of the order of phenomena both 

 in the individual and in the series. There come up 

 for his consideration the links uniting to the body 

 that spiritual element which, in the actions of the 

 individual, is never seen by us in operation, save 

 in the closest association with physical structure. 

 And the yet larger speculation, Is spirit or matter 

 the prior, the underlying, unchangeable, and eternal 

 element, constantly obtrudes itself on the horizon 

 of more limited inquiries. 



These are all questions which have been much 

 discussed in recent times ; and the order of the 

 appearance of structures having been studied both 

 in the form of palaeontology and development, it is 

 not wonderful that speculations have been rife as 

 regards not only the nature, but likewise the origin 

 of life, of species, of matter, and intelligence. 



That there is a certain unity binding together 

 the most diverse forms of organization is a doctrine 

 which, at this date, I fancy no one will deny. The 

 similarity of the units of life in plant and animal 

 texture, and the general, if not altogether universal, 

 pervasion of sexual distinction, are illustrations of 



