196 THE STUDY OF ANIMAL LIFE CHAP. 



of time. As Meredith says : " Ugly is only half-way 

 to a thing." But -those who have not already perceived 

 this will not see much meaning in the assertion, nor in 

 Samuel Butler's opinion that " form is mind made 

 manifest in flesh through action," nor in Walt Whitman's 

 eulogy : 



" I believe a leaf of grass is no less than the journey- work of the 



stars, 

 And the pismire is equally perfect, and the grain of sand, and 



the egg of the wren, 



And the tree-toad is a chef-d'oeuvre for the highest, 

 And the running blackberry would adorn the parlours of heaven, 

 And the narrowest hinge in my hand puts to scorn all machinery. 

 And the cow crunching with depressed head surpasses any statue, 

 And a mouse is miracle enough to stagger sextilk'ons of infidels ! ' 



Apart from artistic considerations, there is much that 

 interests us in the outsides of animals. We can readily 

 understand that the radial symmetry of sea-anemones 

 and jellyfishes is well adapted for a sedentary or for a 

 drifting mode of life, while bilateral symmetry, with a 

 head-end and a tail-end, with a right-side and a left- 

 side, and one median dorso-ventral halving plane is 

 suited for a more active and assertive life, for pur- 

 suing prey and mates, or for avoiding enemies. It was 

 one of the greatest steps in organic evolution when 

 animals, probably some worm-types to start with, began 

 the habit of moving with one end of the body always in 

 front. As Prof. Hickson points out, there appears to be 

 greater plasticity or variability of architectural detail 

 in the radially symmetrical, especially when colonies are 

 formed, and greater specific individuality and archi- 

 tectural constancy in the bilateral. 



When we press below the surface of the animal we 

 begin what is called structural analysis. We have to 

 distinguish great systems of parts, such as the skeletal 

 system, the muscular system, the nervous system. We 

 have to identify great organs, such as brain, heart, lungs, 

 and liver. We analyse further and find that these are 

 built up of tissues, such as muscular, nervous, connec- 

 tive, and glandular tissues. With the high power of the 



