'cii. IV.] SUBSTITUTION OF NERVE-ACTIONS. 



287 



Fter being decapitated. A horse with his head shot off by a 

 jannon-ball kicks when it is struck down, just as it usually 

 loes when its war-instinct is otherwise excited. Examples of 

 ithis kind are numerous. 



560. It scarcely requires proof, that the sentient actions of 

 the instinct of propagation may take place as nerve-actions 



'om external impressions only. Crickets allure to sexual 

 [congress, after decapitation, by the vibration of their wings; 

 land Kedi, Bibiena, and others, have observed that butterflies, 

 [after having copulated but once in their lives, repeat the func- 

 ition perfectly when decapitated, and the females after sexual 

 jcongress, deposit their eggs as carefully as if excited thereto by 

 [their instinct. 



561. The preceding statements fully estabhsh the general 

 [fact, that all this class of sentient actions are only animal 

 imovements, which may be produced as perfectly by the vis 



wsa only, as by the cerebral forces ; in many animals they 

 [are the preordained and adapted results of external impressions 

 ^made by nature on the nerves for the express purpose ; in many 

 )thers, are at the same time sentient actions, being produced 

 |by the co-operation of the cerebral forces, and in this class are 

 -at one time excited as nerve-actions only, at another as both 

 sentient actions and nerve-actions ; and in newly-born animals, 

 which are insensible to the external impressions of the instincts, 

 are developed as nerve-actions only. Further, the acts which 

 btake place in connection with its principal and secondary 

 /instincts, characterise an animal, and determine its sensational 

 -character and leading propensities (295), constitute no proof 

 ^that such animals are controlled by true instincts, or are en- 

 dowed with the sensational faculty or with mind (437 — 440). 



562. The instinctive passions originate like instincts from 

 obscure sensational stimuli; differing only in this, that the 

 latter are perceived during their continuance (298). Their 

 sentient actions are the same as those of the instincts, but the 

 incidental sentient actions are developed rather according to 

 psychological laws (297). But inasmuch as they arise in the 

 instinct itself, and, consequently, in close connection with the 

 external impressions which excite it, and since the sentient 

 actions of the instinct are excited by the vis nervosa only, and 



, can take place in the same order as if excited volitionally (552), 



