DISEASES OF THE OX AND SHEEP. 427 



death does not result, his vitality may be sapped and under- 

 mined to its very foundations. It is one of the deplorable 

 but yet most true conditions of the existence of any living 

 being, no matter how highly developed, that there is always a 

 grave risk that life may be immensely impaired, and even made 

 to cease, as a result of the inroads of parasitic organisms. From 

 its commencement to its close, life is composed of a series of 

 struggles ; and the foes with which any given man, woman, 

 child, or any animal of whatsoever kind or degree, is liable to 

 be confronted, are by far more numerous and by far more 

 formidable than any of us can adequately conceive. 



In the progress of those subtle processes of equilibration and 

 evolution, whereby the advancement of the race is made 

 possible, the chances cannot but tell greatly against indivi- 

 duals, and it is only by reahsing this that those of us who are 

 fairly healthy and well-off are enabled to see how thankful we 

 ought to be for our preservation, not only from the more or less 

 accidental disasters which may at any moment sweep us away 

 from the face of the earth, but also from the hostile activities of 

 the many animal and vegetable parasites by which we might 

 at any time be grievously afflicted. There is something at once 

 startling and mournful in the thought that men and women of 

 the brightest intellect, and those possessing the strongest and 

 healthiest frames, may be swept into the sea of eternity by the 

 attacks of creatures utterly insignificant ; that the most brilliant 

 career may be blasted by the virus of some deadly fever which 

 may lay low and destroy men, women, and children, rich and 

 poor, good and bad, without discrimination. 



There are, fortunately, two saving clauses to this picture ; for, 

 in the first place, our power to repel such invasions is daily 

 increasing, and, secondly, it may be maintained that possibly 

 there is a future life before us, in which, if we shall be able to 

 look back upon this one, we shall probably do so with no regret 

 that the change has been made from a lower to a higher 

 kind of existence. Nevertheless, it remains indisputable that, 

 optimistic as we may rightly be in regard to the future welfare 

 and good destiny of mankind at large, we cannot but realise the 

 appositeness of Tennyson's query : — 



Are God and Nature then at strife, 

 That Nature lends such evil dreams ? 



