THE LAW OF EVOLUTION. 335 



early times with those used now, we see that in each of our 

 machines several of the primitive machines are united into 

 one. A modern apparatus for spinning or weaving, for 

 making stockings or lace, contains not simply a lever, an in- 

 clined plane, a screw, a wheel-and-axle, joined together; but 

 several of each integrated into one whole. Again, in early 

 ages, when horse-power and man-power were alone em- 

 ployed, the motive agent was not bound up with the tool 

 moved; but the two have now become in many cases fused 

 together. The fire-box and boiler of a locomotive are com- 

 bined with the machinery which the steam works. A still 

 more extensive integration is exhibited in every factory. 

 Here we find a large number of complicated machines, 

 all connected by driving shafts with the same steam-engine 

 all united with it into one vast apparatus. 



Contrast the mural decorations of the Egyptians and 

 Assyrians with modern historical paintings, and there be- 

 comes manifest a great advance in unity of composition 

 in the subordination of the parts to the whole. One of 

 these ancient frescoes is, in truth, made up of a number of 

 pictures that have little mutual dependence. The several 

 figures of which each group consists, show very imperfectly 

 by their attitudes, and not at all by their expressions, the 

 relations in which they stand to each other: the respective 

 groups might be separated with but little loss of meaning; 

 and the centre of chief interest, which should link all parts 

 together, is often inconspicuous. The same trait may be 

 noted in the tapestries of medieval days. Representing 

 perhaps a hunting scene, one of these contains men, horses, 

 dogs, beasts, birds, trees, and flowers, miscellaneously dis- 

 persed: the living objects being variously occupied, and 

 mostly with no apparent consciousness of each other's proxi- 

 mity. But in the paintings since produced, faulty as many 

 of them are in this respect, there is always a more or less 

 distinct co-ordination of parts an arrangement of atti- 

 tudes, expressions, lights, and colours, such as to combine 



