94 LIFE AND ORGANISATION. 



changes of land and sea ; but the farther we recede from our 

 own time into these depths of ages, the more entirely do we 

 lose all analogies of geographical distribution. 'Even in 

 some of our most recent strata,' as Professor Owen remarks, 

 f fossils occur for which we must seek the representatives in 

 America ; and to match the mammalian remains from Oolite, 

 we must bring specimens from the Antipodes.' 



In treating of these various questions which have relation 

 to Life as the subject of modern science, we have only par- 

 tially alluded to the enquiry denoted by the special term of 

 Animal Physiology; the history of those organs and func- 

 tions through which vitality receives and maintains its 

 individual existence. This subject, in truth, is too vast in 

 outline as well as details, and the discussions it embraces too 

 various and important, to be dealt with in any single Article, 

 even exclusively thus directed. The functions of nutrition 

 and assimilation, of circulation and respiration, of 

 secretion and excretion, and of the nervous system in its 

 several parts, all these have been the objects of refined 

 experiment and sedulous observation by the physiologists 

 and physicians of our day ; and with results which give a 

 new face and form to this branch of science. But while 

 putting aside the subject at large, there is one class of 

 the functions just named which we cannot wholly omit 

 when treating of physical science in its relation to vital 

 phenomena. We mean those wonderful functions which are 

 fulfilled through the instrumentality of the nervous system, 

 and which we cannot err in describing as of far higher 

 interest than any others of the animal economy ; seeing that 

 they connect the conscious being, whatever its grade in 

 creation, with every part of its own organisation and with 

 the world without. Sensations in all their forms, volitions 

 in all their acts, find transmission solely through this portion 

 of structure ; one so little intelligible to the eye or outward 



