CHAPTER IV. 

 DEATH. 



982. WHEN the animal kingdom is surveyed from a broad 

 standpoint, it becomes obvious that the ovum, or its correlative 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 which 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 successive 

 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 useless, 

 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 effected 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 circu- 

 lation, the access of air to the haemoglobin 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, 



F. 99 



