378 Appendix 
III. 
The hypothesis here presented of the mnemonic 
nature of the affective tendencies in general is further 
confirmed by other examples of more special affec- 
tivities which have also originated by way of “habit” 
and yet bear special relations to the environment since 
they affect only one part or another of the organism 
and manifest an activity only periodically or intermit- 
tently. They are especially in evidence in the higher 
animals and in man most of all. 
As a typical instance it will be sufficient to consider 
maternal love. 
Evidently the habit of having certain relations of 
parasitism, or, in general, of symbiosis, with the progeny 
throughout a long series of generations has become 
gradually transformed in a mnemonic way into affective 
tendencies towards these relations. 
“Comparative ethology,” says Giard, “shows us most 
clearly that the relations between the parent organism 
and its progeny are in principle absolutely the same as 
those existing between a parasite and the animal it lives 
upon, and that after a period of unstable equilibrium in 
which one or other of the two associated organisms 
suffers to the advantage of its companion there is a 
tendency to the establishment of a definite position of 
mutual (mutualiste) equilibrium.” '° 
This is true for instance of the relations of internal 
incubation, which though first sought and effected by 
the embryo itself in some phase of its development for 
the purpose of nutrition or some other advantage, and 
19A. Giard, “Les origines de l’amour maternel,’ Revue des 
idées, April 15, 1905, p. 256. 
