294 ON LIFE AND ORGANISATION. 



their minutest structures, are peculiar. They seldom, pro- 

 bably never, present straight margins, flat surfaces, or angles. 

 They are very generally spheroidal, but never absolutely 

 spherical. Ellipsoidal and paraboloidal surfaces are met with, 

 and still more complex forms occur in connection with that 

 essentially organic curve, the spiral. Curves of double curva- 

 ture, surfaces with complex geometrical relations, constitute 

 the predominating forms in organisation. 



As the matter of the living organism is in continual flux, 

 so we find that the fresh matter which is constantly added to 

 it becomes united to it, not at its outer surface, or at the outer 

 surface of any of its minutest organised parts, but in its 

 interior ; at every part of which, again, the fresh matter is 

 united to the ultimate organised particles, not at their exterior, 

 but by passing into their interior, to be distributed therein for 

 final union. 



Connected with this latter peculiarity is the remarkable 

 series of phenomena presented during the development of the 

 organism, while still in connection with, or after detachment 

 from, its parent. Science recognises no process of develop- 

 ment except that of the individual organism from pre-existing 

 parents of the same unalterable species. The development of 

 the organism resembles no other series of material changes in 

 any system in nature. Even the minutest part of an organ- 

 ism, however complicated it may be, is evolved or unrolled 

 from within outwards. Cell after cell, fibre after fibre, organ 

 after organ, each in its own peculiar but strictly organic 

 manner, appears at the centre of its own organic district. 

 They make their appearance at set times, at stated periods, 

 and in ever-increasing numbers, to the close. Passing off from 

 their original centres, they assume their proper places in the 

 composition of the complex machine-cell, commencing origi- 

 nally in the interior, but frequently protruding during the 

 process, parts of slow become enveloped by others of more 



