1888.] on Antagonism. 289 



which has to make an ignominious retreat. It is a curious chapter in 

 the history of the struggles of molecular forces, and probably similar 

 contests between light and chemical or physical attractions go on in 

 many natural phenomena, some forms of blight and some healthy 

 vegetable changes being probably dependent on the varying effects of 

 light, and conditions, electrical or otherwise, of the atmosphere. 



Let us now pass on to organic life. A blade of grass, as Burke, 

 I believe, said as a figure of sj^eech, is fighting with its neighbours. 

 It is robbing them, and they are trying to rob it — no agreement or 

 contract, simply force opposed to force. This struggle is good for 

 the grass ; if it got too much nutriment it would become diseased. 

 The struggle keeps it in health. The rising of sap in trees, the 

 assimilation of carbon, the process of growth, the strengthening 

 themselves to resist prevalent winds, and many other instances might 

 be given, which afford examples of the internal and external struggles 

 in vegetable life. 



I will now proceed to consider animal life, and in this case I will 

 begin with the internal life of animals, which is a continual struggle. 

 That great pumj) the heart is continuously beating — that is, conquer- 

 ing resistance. It is forcing the blood through the arteries, they 

 assisting in squeezing it onwards. If they give way, the animal dies ; 

 if they become rigid and resist too much, the animal dies. There 

 must be a regulated antagonism, a rhythmical pulsation, the very term 

 involving force and resistance. That 'the act of breathing is antago- 

 nistic scarcely needs argument. The muscular action by which the 

 ribs are made to ojien out and close alternately, in order to inhale and 

 exhale air, and other physiological changes which I cannot here go 

 into, necessitate a continuous fight for life. So with digestion, assi- 

 milation, and other functions, mechanical and chemical forces and 

 resistances come into play. 



Since this lecture was written, I have heard of a discovery made, 

 I am informed, by Prof. Metschnikoff, and which has brought to light 

 a singular instance of internal antagonism. He is said to have 

 proved that the white corpuscles of the blood are permanent enemies 

 of Bacteria, and by inoculation will absorb j^oisonous germs ; a re- 

 current war, as it appears, going on between them. If the corj)uscle 

 is the conqueror, the Bacteria are swallowed up, and the patient lives. 

 If the corpuscles are vanquished, the patient dies, and the Bacteria 

 Hve, at all events for a time. If the theory is founded, it affords a 

 strong additional argument to the doctrine of internal antagonism. 

 Possibly if there were no Bacteria, and the corpuscles had nothing to 

 do, it would be worse for them and the animal whom they serve. 



Let us now consider the external life of animals. I will take as 

 an instance, for a reason which you will soon see, the life of a wild 

 rabbit. It is throughout its life, except when asleep (of which more 

 presently), using exertion, cropping grass, at war with vegetables, &c. 

 If it gets a luxurious pasture it dies of repletion. If it gets too little 

 it dies of inanition. To keep itself healthy it must exert itself for 



