MENTAL DIFFERENCE AND DISOEDER. 233 



as appropriate to, and represents a condition as common in 

 the dog as in man. In that animal, indeed, the emotion is 

 so intense sometimes as to be beyond the power of its ex- 

 pression (Houzeau). We frequently hear of its 'frantic 

 state of joy ' on the appearance of a long absent master or 

 mistress. The pleasurable excitement of sport in the sport- 

 ing dog, just as in the boy at his football, boating, or cricket, 

 is apt to become excessive, and therein or thereby morbid, 

 inducing, as sequelse, conjoint mental and physical evils. 

 Excessive joy would appear to have been the cause of sudden 

 and intense mental excitement, amounting to ephemeral 

 mania, in Berkeley's bloodhound Druid, f after the death of 

 a deer on the conclusion of a severe chase.' But to joy at 

 success in such a case must be added, in estimating the 

 causation of such mental excitement, the physical as well as 

 the mental strain, the bodily fatigue as well as the triumph 

 of victory. 



In certain other animals there is occasionally a perfect 

 wildness of joy,' great intensity of mental excitement 

 from pleasurable emotions. Thus Darwin speaks of the 

 ' madness of delight ' in a stickleback (fish), meaning, no 

 doubt, exuberance of joy, or uncontrollable animal spirits. 

 Houzeau describes the joy of the Brahminy ox at the sight 

 of fresh food after a sea voyage as extravagant; and the 

 mongoose is represented as being in a ' frenzy of happiness 

 at the death of an enemy. Gurney speaks of demonstrations 

 of exuberant joy in the horse. What Pierquin describes as 

 'joyous mania' may be, and probably is, what medical authors 

 mention as ' ecstasy ' a mere excess of delight, a pleasurable 

 feeling, for the moment uncontrollable and inconveniently 

 demonstrative, one of the major forms of joyous excitement. 



The natural timidity or tiinorousness of certain animals 

 has an intimate relation both to the facility with which fear 

 may be generated, and to the probability of such fear, when 

 generated, passing into suspiciousness and delusion. In some 

 animals timidity is extreme; and in such cases they are 

 usually otherwise eminently ( nervous ' or sensitive. The 

 nervous timidity in such cases, moreover, is usually con- 

 genital has been transmitted from a line of ancestry, in 



