PSYCHICAL LIFE AND INSTINCT. 93 



clearly distinguishable than in the higher, and there are numerous 

 senses of an intermediate character for the purpose of testing the 

 surrounding medium. 



The sense-organs of the lateral line of Fishes and Salamanders, and 

 the organs resembling taste-buds of the Hirudinea and Chsetopoda 

 been described as organs of a sixth sense. They probably bring 

 abowNertairi sensations referring to the quality of the water. 



PSYCHICAL LIFE' 1 ' AND INSTINCT. 



The higher animals are not only rendered conscious of the unity 

 of their organization by their feelings of comfort and discomfort, 

 pleasure and pain, but also possess the power of retaining residua 

 of the impressions of the outer world conveyed through the. senses, 



'and of combining them, with simultaneously perceived conditions of 

 their bodily state. In what manner the irritability of the lower pro- 

 toplasmic organisms leads by gradual transitions and intermediate 

 steps to the first affection of sensation and consciousness is as 

 completely hidden from us as are the nature and essence of the 

 psychical processes which we know are dependent on the movement 

 of -matter. 



; We are, however, justified in supposing that a nervous system 

 is indispensable for the development of these internal conditions 

 which may be compared with that condition of our own organization 

 called consciousness. Again, as animals have sense-organs capable 

 of receiving impressions of definite quality from external causes, 

 together with a capacity for retaining in their memory residua of 

 their perceptions, and the power of connecting them with present and 

 with the recollection of past states of bodily sensation so as to form 

 judgments and conclusions, they possess all the conditions essential 

 for the operation of the intelligence; and, as a matter of fact, they 

 do manifest in an elementary form nearly all the phenomena which 



, distinguish human intelligence. 



The actions of animals are not only voluntary, the result of experi- 

 ence and intellectual activity, but are also largely determined by 

 internal impulses which work independently of consciousness, and 

 cause numerous, often very complicated, actions useful to the organism. 

 Such impulses tending to the preservation of the individual and the 



* W. Wundt, " Vorlesungen tiber die Menschen und Thierseele." 2 Bde. 

 Leipzig, 1863. W. Wundt, " Grundziige der physiologischen Psychologic," 

 Leipzig, 1874. 



