ZOOLOGY. 337 



to do so, by the conviction that the least movement is impossible. 

 The misinterpretation of sensory impressions is continually seen in 

 persons who are subject to absence of mind, who make the most ab- 

 surd mistakes as to what they see or hear, taste or feel, in consequence 

 of the pre-occupation of the mind by some train of thought which 

 renders them unable rightly to appreciate the objects around them. 

 In such persons, too, the memory of the most familiar things as the 

 absent man's own name, for example, or that of his most intimate 

 friend - - is often in abeyance for a time ; and it requires but a more 

 complete obliteration of the consciousness of the past, through the 

 entire possession of the mind by the intense consciousness of the pres- 

 ent, to destroy the sense of personal identity. This, indeed, we often 

 do in effect lose in ordinary dreaming and reverie. The essential 

 characteristic of both these 'states, as of the " biological " condition, 

 is, the suspension of voluntary control over the current of thought, so 

 that the ideas follow one another suggestively ; and however strange or 

 incongruous their combinations or sequences may appear, we are 

 never surprised at them, because we have lost the power of referring 

 to our ordinary experience. There is one phenomenon of the " bio- 

 logical " state,' which has been considered pre-eminently to indicate 

 the power of the operator's will over his subject ; namely, the induc- 

 tion of sleep, and its spontaneous determination at a given time 

 previously ordained, or by the sound of the operator's voice, and that 

 only. It* is well known 'that the expectation of sleep is one of the 

 most powerful means of inducing it, especially when combined with 

 the withdrawal of the mind from everything else which could keep its 

 attention awake ; both these conditions are united in an eminent 

 degree in the state of the biologized subject whose mind has been 

 possessed with the conviction that sleep is about to supervene, and is 

 closed to every source of distraction. The waking at a particular time 

 may also be explained by the influence of expectation. Thus, how- 

 ever strange the phenomenon of the " biological " state may at first 

 sight appear, there is not one of them which, when closely scrutinized, 

 is not found to be essentially conformable to facts whose genuineness 

 everv phvsiologist and psychologist is readv to admit. It is not, how- 



* ^ ***ii i 



ever, in any large proportion of individuals that this state can be 

 induced ; probably not more than one in twenty, or at most one in 

 twelve. Males appear equally susceptible of it with females ; so that 

 it cannot be fairly set down as a variety of " hysterical " disorder. 

 The lecturer proceeded to inquire, whether any such physiological 

 account can be given of this state as shall enable us to refer it to any 

 of the admitted laws of action of the nervous system ; and in order to 

 prepare his auditors for the reception of his views, he gave a brief ex- 

 planation of those phenomena of " reflux " action (now universally 

 recognized by physiologists) in which impressions made upon the 

 nervous system are followed by respondent automatic movements. The 

 movements which we term voluntary or volitional differ from the 

 emotional and automatic, in being guided by a distinct conception of 

 the object to be attained, and by a rational choice of the means em- 



