300 SYMBIOGENESIS 



symbiotic "elan" the body needs some preparation, i.e., 

 maturation or incubation to effect all the necessary 

 simultaneous changes. If an organism is struck in its most 

 vulnerable points it cannot afford to throw the whole burden 

 of defence on that particular part, because it would interfere 

 too much with the part's vital and highly specialised 

 functions ; but it must call to arms the whole symbiotic com- 

 munity. This general " mobilisation," of course, takes time. 

 It is a well-known fact that many otherwise curable illnesses 

 become fatal if sudden heart failure ensues, possibly because 

 frequently the heart is too unprepared to meet sudden 

 exigencies. Given due time and due warning even the busy 

 heart, instead of breaking down, might have found it possible 

 to give more assistance at the critical moment. 



We may also infer from the above considerations what 

 scope there is in a general way through metabolic fluctua- 

 tions, i.e., through changes of feeding habits for various 

 possibilities of undesirable and pathogenetic developments. 



We may ask indeed what is it that preserves the constancy 

 of a species from the perils of promiscuous unions? Do not the 

 phenomena of anaphylaxis indicate that there must be in Nature 

 a great need of a definite and persistent principle, such as the 

 symbiogenetic principle for which I contend, in virtue of 

 which a species may be guarded against the dangers of drifting 

 into pronounced pathogenesis ? We have seen already that 

 there is such a principle, and in view of these pathogenetic 

 possibilities it is clear that the self-preservation of the organic 

 world necessitated the establishment of some such principle. 



As a further instance of lasting injurious effects produced 

 by certain albuminous poisons, we get the following from 

 Prof. Richet: 



A vegetable albuminous extract of Hura crepitans so alters nutri- 

 tion that at the end of three months the animal still shows the effect of 

 it ; in general, dogs on which I have experimented do not completely 

 regain their former weight. 



This example also brings us again near that prolific source 



