[7] 



>tion of instinct, which makes the little animal shrink 

 from the touch. 



From the Hydrse evolved the Medusae, which, instead 

 of being dependent entirely on neuro-muscular cells like 

 the parent forms, developed minute sets of nerves and 

 muscles, by the use of which they became enabled to 

 swim about easily and at their own will and pleasure. 

 We get in this little animal the first appearance of real 

 nerve function, or conductibility of stimulus along the 

 nervous fibre to a muscle which it causes to contract a 

 totally different function to the contraction of the whole 

 body upon a stimulus being applied to it, as in the case 

 of the Hydrae. 



In the worm forms, which evolve from the Gastraaada, 

 we come across the first attempt at special sense-organ 

 formation, in the shape of depressions on the integu- 

 ment of the body. The Himatega, or sack-worms, 

 possess a rudimentary spinal cord, and were the parents 

 of the first true vertebrates, organisms without skulls 

 or brains, but with a true vertebral cord. These little 

 vermiform animals, in addition to their rudimentary 

 spinal cords, exhibited upon the surface of the body 

 several small depressions, which answered the purpose of 

 a set of special sense-organs, one tiny depression being 

 set apart especially for the perception of light waves, 

 another for the perception of sound waves, another 

 for the perception of odours, etc. ; and thus gradually 

 came about that wonderful evolutionary process by which 

 bodies became endowed with more or less perfect special 

 sense-organs. 



As the animal kingdom developed into higher and 

 higher forms of life, and skulls and brains became the 

 order of the day, the special sense-organs became 

 possessed of larger powers, at the same time that the 

 whole nervous organisation assumed higher and more 

 complex functions, resulting eventually in a very gradual 

 unfolding of the most wonderful of all the latent poten- 

 tialities of universal life the marvel of consciousness. 

 This is the present climax of Nature's evolution, the 

 grandest and most awful achievement of that hidden and 

 mysterious force which baffles comprehension, and beside 

 which all things seen, heard, or felt pale into insignificance. 



