THE GENERAL CONSTITUTION OF LIVING BEINGS. 3 



the sum of the properties inherent in each sort of element, 

 while the characteristics of the fundamental element pre- 

 dominate. The accessory elements in a manner restrain 

 the too great activity of this latter, and thus take part in 

 giving to the tissue properties of a secondary order indeed, 

 but indispensable to the discharge of its duty, which is thus 

 the result of manifold properties. When the texture of 

 these organic webs is studied under a microscope, we are 

 often astonished at the prodigious complexity they exhibit. 

 Nothing is so curious as the disposition and arrangement 

 of all these tiny centres of life, some round, others polyhe- 

 dric, others thread-like, others again tubular, and all so 

 small that the humblest flesh-worm is a monster beside 

 them. Sometimes the fibres are tangled inextricably, like 

 dense ivy around an aged trunk ; sometimes there is a 

 singular net, formed by the capillaries with fine meshes, 

 in which the cells crowd and crush themselves out of shape. 

 Sometimes we find clusters in which little bladders are 

 arranged along a crooked channel ; sometimes there are 

 layers, piled one on another, resembling geological strata. 

 In a word, the arrangement of the elements is exceedingly 

 diversified, and, if we might say that the tissues are words 

 in which anatomical elements stand for the letters, it must 

 be added that the order of the latter is much more compli- 

 cated than is the case with the terms of spoken language, 

 and very differently too. 



The nerve-tissue, the real masterpiece of vital force, has 

 been well understood only since histology has disclosed to 

 us all the elements* of that fragile whitish pulp. The 

 structure of the ganglia, the connections they have with 

 the nerves, the difference between nerve-tubes and nerve- 

 cells, have been made out by Robin. He it was, too, who 

 discovered the lymphatic vessels of the brain-substance. 

 These lymphatics encircle the blood-vessels traversing the 

 central nerve-tissues in such a way that the latter are com- 



