138 GLIMPSES OF NATURE. 



to build up bones, to form muscles, and to make the 

 various secretions. The aristocrats are the nerve- 

 cells, which are by no means an idle plutocracy, 

 however, but which work hard enough in the ruling, 

 direction, and governance of the frame. 



There is perfect division of labour in the living 

 state. One group of cells does not interfere with the 

 work of another group. Each piece of labour, from the 

 building of bone to the making of gastric juice, is carried 

 out independently and thoroughly by workers set apart 

 for the given purpose. The economy of a bee's hive 

 is not more rigidly ordered than is the work of our 

 own body in respect of its labourers and their specific 

 duties ; and in the vast proportion of their affairs 

 these workers of ours are self-directive, even while 

 they own the supremacy of brain and nerves as their 

 controlling power. 



If we think of the countless operations which have 

 to be undertaken from hour to hour to maintain our 

 bodies in action, we may begin to realise what perfect 

 co-operatiori really means, and what this colonial con- 

 stitution of ours implies. For example, saliva has to 

 be secreted, for the purpose of digestion in the mouth, 

 and for other functions as well. This fluid is supplied 

 by three pairs of salivary glands. 



Now, the working and essential parts of these glands 

 are living cells, which, out of the blood (as the raw 

 material) supplied to the glands, secrete saliva, which is 

 the manufactured product. Again, tears have perpetu- 

 ally to be made for washing the eyes. This secretion 

 is supplied by a couple of tear-glands. Here, again, 

 are cells, different from those of the salivary glands, 

 and making out of the blood a very different secretion 

 to that of the mouth. The cells of the gastric glands 



