2 LEISURE-TIME STUDIES. 



ing as we may hold them to be more or less essential. 

 And in what follows I shall endeavour to show that Biology 

 may claim to hold, not merely and as usually regarded an 

 incidental, but an essential and necessary place and power 

 in ordinary school-training. 



A simile of biological kind may, perhaps, serve in some 

 degree to illustrate the position on which I take my stand. 

 A very important principle, known as that of the " special- 

 isation of functions," assists the naturalist in determining 

 the place of different organisms in the scale of being. By 

 the aid of this principle he is led to assign to each organism 

 a position of high or low grade, according as the functions 

 of its body are of a more or less complicated kind. Com- 

 plication of functions in the living organism results from 

 their specialisation or differentiation ; in other words, the 

 higher the organism, the more thoroughly specialised or 

 broken up into minor parts is each function of its frame. 

 In any low microscopic Protozodn such as the Amceba 

 the functions are not specialised at all. When such a being 

 eats, for example, it grasps food by any portion of its body, 

 which is composed of a speck of almost structureless pro- 

 toplasm. And any part of the soft protoplasmic frame 

 serves equally with any other part, for the digestion of that 

 food. But when we regard the higher animal, we notice 

 that not only are distinct organs set aside or specialised for 

 the function of taking in food, but every part of the great 

 function of digestion is subserved by separate organs, allo- 

 cated each for its special work. Thus, we say that, in the 

 latter form, "specialisation of functions" exists; and the 

 animal is a higher animal than the Protozoon, because, 

 in the latter, any part seemed to subserve any function 

 just as the " maid-of-all-work " represents in herself the 

 specialised labours of the numerous staff of servants belong- 

 ing to the great mansion. Conformably with this principle 

 would I argue of the study of Biology in its relations to 

 commonplace education. As the specialisation in functions 

 advances with the rank and value of the organism, so, I 



