CHAPTER IV. 

 DEATH. 



722. WHEN the animal kingdom is surveyed from a 

 broad standpoint, it becomes obvious that the ovum, or its cor- 

 relative the spermatozoon, is the goal of an individual existence; 

 that life is a cycle beginning in an ovum and coming round to 

 an ovum again. The greater part of the actions which, looking 

 from a near point of view at the higher animals alone, we are 

 apt to consider as eminently the purposes for wiiich animals 

 come into existence, when viewed from the distant outlook 

 whence the whole living world is surveyed, fade away into the 

 likeness of the mere byplay of ovum-bearing organisms. The 

 animal body is in reality a vehicle for ova; and -after the life of 

 the parent has become potentially renewed in'the offspring, the 

 body remains as a cast-off envelope whose future is but to die. 



Were the animal frame not the complicated machine we have 

 seen it to be, death might come as a simple and gradual disso- 

 lution, the 'sans everything' being the last stage of the succes- 

 sive loss of fundamental powers. As it is, however, death is 

 always more or less violent; the machine comes to an end by 

 reason of the disorder caused by the breaking down of one of its 

 parts. Life ceases not because the molecular powers of the whole 

 body slacken and are lost, but because a weakness in one or other 

 part of the machinery throws its whole working out of gear. 



We have seen that the central factor of life is the circulation 

 of the blood, but we have also seen that blood is not only use- 

 less, but injurious, unless it be duly oxygenated ; and we have 

 further seen that in the higher animals the oxygenation of the 

 blood can only be duly affected by means of the respiratory 

 muscular mechanism, presided over by the respiratory centre in 

 the bulb. Thus the life of a complex animal is, when reduced 

 to a simple form, composed of three factors : the maintenance of 

 the circulation, the access of air to the hemoglobin of the blood, 

 and the functional activity of the respiratory centre ; and death 

 may come from the arrest of any one of these three. As it has 

 been put, death may begin at the heart or at the lungs or at the 



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