in the Decapod Crustacea. 343 



Rhizocephala that any misfortune happens to tlie latter. But 

 the same thing takes place if we place together several females 

 loaded with eggs ; each one defends her own, but does not 

 hesitate to devour those of her neighbours. 



It cannot be objected to this view that the males are infested 

 as well as the females, for these infested males are emascu- 

 lated and acquire the instincts of the female, like the capons 

 or the unfertile hybrid pheasants, which sit on the q^^^ and 

 bring up the young *. 



VII. 



Besides the intrinsic interest they possess the observations 

 that we have just brought forward have considerable import- 

 ance from various points of view. 



1. In the first place it is probable that ignorance of the 

 modifications produced by the parasite in the external sexual 

 characters of its host has frequently given rise to errors 

 analogous to those of Fraisse, and consequently this diminishes 

 to a certain extent the value of the older statistics with re^'ard 

 to the Rhizocephala, a value which was already not too great 

 from many other considerations. 



* We have indicated elsewhere that maternal love has its origin in a 

 simple reflex action which is agreeahleto the parent and occurs sometimes 

 in the form of paternal love (fishes), sometimes in that of maternal love 

 properly so called (birds and Mammalia). It is remarkahle to find tliat 

 this explanation was foreseen by Mauduyt as early as 1783. Thus in the 

 ' Eiicyclopedie ' (Oiseaux i. art. Coq, p. 61), with regard to the attach- 

 ment of the hen for her eggs and chickens, w^e read as follows : — 



" Is this attachment rational, or is it the sensual product of the con- 

 tact of the e^^ ? What might lead us to admit the second supposition is 

 that this attachment on the part of the hen does not relate to her own 

 eggs only, but she sits with the same assiduity and perseverance tliat she 

 shows towards her own eggs upon all those which are given to her, of 

 ■whatever kind they may he, and even upon inorganic bodies which have 

 no resemblance to eggs but in their form. It is not tlie colour that 

 deceives her, for I have given a hen to sit the eggs of a Cayenne bird of 

 a very dark greenish-blue colour, and she did not quit them until I took 

 them away." 



Mauduyt also perceived that the female psychical characters of castrated 

 males were directly acquired and not the resvilt of the development of a 

 latent instinct. Thus we read (I. c. art. Coq, p. 618) with regard to 

 capons employed in brooding : — " To succeed in this enterprise the belly 

 of the capon to be employed is plucked and rubbed with nettles ; he is 

 then shut up in a room with two or three chickens ; these young animals, 

 approaching tlie capon in search of the warmth which they found under 

 their mother, make him experience a coolness which is agreeable, because 

 it moderates the burning sensation that he feels ; he lends himself in con- 

 sequence to their washes, and in a little time the business of brooding 

 becomes so agreeable to him that he will hardly allow the chicken*^ to 

 escape from under his wings." 



24* 



