NA TURE 



541 



THURSDAY, OCTOBER 3, i{ 



PSYCHOLOGY OF PROTOZOA. 



The Psychic Life of Micro-organisms : a Study in Covi- 

 paratii'e Psychology. By Alfred Binet. Translated from 

 the French by Thomas McCormack. (Chicago : The 

 Open Court Publishing Company, 1889.) 



Psycho-physiologische Protisten-Studien : experimentelle 

 Untersuchungen. Von Dr. Max Vervvorn. (Jena : 

 Gustav Fischer, iSSg.) 



THE first of these two works on the psychology 

 of Protozoa is disappointing. Its main object, 

 as indicated in its title, is to investigate the claims 

 which from time to time have been put forward on behalf 

 of unicellular organisms to the possession of conscious- 

 ness and a certain low order of mental life. Therefore, 

 looking to the position which M. Binet has gained as a 

 successful worker in other departments of psychological 

 inquiry, we were prepared at his hands to meet with a 

 judicious treatment of facts in the light shed by a specially 

 instructed mind. But, far from this, what we do meet 

 with is the special pleading of an advocate who seems to 

 hold a brief on behalf of his little friends, and is deter- 

 mined to force them into a position of intellectual 

 prominence, no matter at what cost of psychological 

 absurdity. Indeed, were it not that the title-page declares 

 the authorship of this work, no one could possibly have 

 supposed that it had been written by a man who had ever 

 opened an elementary text-book on mental science. 



In justification of so severe a criticism one or two 

 quotations may be supplied. With regard to suprise and 

 fear he says : — " We may reply upon this point, that there 

 is not a single infusory that cannot be frightened, and 

 that does not manifest its fear by a rapid flight through 

 the liquid of the preparation. If a drop of acetic acid be 

 introduced beneath the cover-glass, in a preparation 

 containing quantities of Infusoria, the latter will at once 

 be seen to flee in all directions like a flock of frightened 

 sheep." His test to prove memory is — " Every time 

 an animal repeats the same action under influence of the 

 same excitations, that fact proves that the animal is 

 possessed of memory." His one criterion of instinct 

 is — " Preadaptation to an end not present, but remote." 

 After such examples, it would be needless to adduce 

 more.^ In no part of the book is any distinction drawn 

 between activities as reflex or automatic, and conscious 

 or intentional ; therefore, if a Protozoon performs any 

 action which is in the smallest degree adaptive, the fact 

 is always taken as in itself sufficient evidence of intelligent 

 volition. Thus, to go no further than the above quotations 

 from his preface, it never seems to have occurred to 

 M. Binet that "rapid flight" in the presence of a 

 stimulating agent may be due to causes other than 

 " fear " ; that every excitable tissue (whether iii situ 

 or excised) which repeats the same action under 

 influence of the same excitation is not forthwith ac- 



Perhaps it is fair to M. Binet to state that these examples are drawn from 

 his preface, which is mainly concerned with an attempt to show that the present 

 writer has not done justice to the mental endowments of the Protozoa. This 

 criticism the present writer has fully answered in the Open Court, July 

 zi, 1889. 



Vol. XL.— No. 1040. 



credited by an experimental physiologist with any 

 psychological " memory " ; or that the heart need not 

 necessarily be supposed to beat by "instinct," because 

 each diastole is a " preadaptation " to the next systole. 



But not only do we everywhere encounter this astonish- 

 ing disregard of the most elementary principles of 

 psychology : we are equally surprised at what may be 

 termed a void of general sagacity. For example, in 

 M. Binet's own opinion the strongest evidence he has to 

 adduce in favour of intelligence on the part of " micro- 

 organisms" consists in the behaviour of spermatozoa 

 and spermatozoids towards ova and ovules. Thus, for 

 example, he does not hesitate to say, by way of a general 

 conclusion on this matter, " In fine, the spermatic element, 

 in directing itself toward the ovule to be fecundated, is 

 animated by the same sexual instinct that directs the 

 parent organism towards its female " ! In particular, he 

 quotes the interesting researches of Prof. Pfeffer, who 

 found that spermatozoids are strongly attracted by certain 

 solutions (malic acid, &c.), so that they will crowd into a 

 pipette filled with these solutions, even though the latter 

 be strong enough to cause their death. Now, to any 

 ordinary common-sense it must appear that in these facts 

 we have evidence pointing directly away from the 

 hypothesis of intelligent adjustment, and therefore 

 towards the simpler hypothesis of some kind of chemical 

 — or physiological — affinity. 



Upon the whole, then, as we have said, M. Binet's 

 work is disappointing ; and, we may now add, the dis- 

 appointment arises not only on account of its astonishing 

 weakness in psychology, but also from its want of full 

 acquaintance with the literature of the subject, and an 

 absence of any original investigations on the part of the 

 author himself. 



Of quite a different stamp is the work of Dr. Vervvorn. 

 Charged throughout with the experimental work of a 

 physiologist, and with the analytical powers of a well- 

 instructed mind, these "Protisten-Studien" are of much 

 value both from a scientific and a philosophical point of 

 view. Like M. Binet, Dr. Verworn has set himself 

 primarily to consider the question as to whether, or how 

 far, the Protozoa ought to be accredited with mental 

 faculties. Therefore a considerable part of his elaborate 

 treatise is devoted to an exposition of those psychological 

 principles, a clear definition of which is so essential to any 

 adequate treatment of this question. The exposition is 

 judicious, and leads to the general conclusion that we 

 have no evidence at all of even the lowest degree of 

 mental life on the part of any of the unicellular organisms. 

 In this connection we may remark that, while M. Binet 

 quotes from an earlier paper Dr. Verworn's observations 

 on the " house-building " habits of Diffliigia urceolata 

 as one of the most unequivocal examples of Protozoon 

 intelligence. Dr. Verworn himself here furnishes a 

 crushing refutation of this view. For he finds, as a 

 result of experiments with powdered glass, that the 

 Dijfflugia will crawl about among the particles without 

 collecting any, so long as it is left undisturbed ; but when 

 irritated by shaking, its pseudopodia retract, and, while 

 doing so, exude sticky little drops, which cause any 

 minute particles over which they happen to pass to adhere 

 and be carried along with the retracting filament, until 



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