Literary Notices. clxxvii 



the trigeminus (via ciliary nerves) to the facial — not from the opticus 

 — and hence we cannot speak of vision in the matter. But again 

 granting that optic fibres transmit the stimulus, reflex connections ef- 

 fected in the pulvinar, corpus geniculatum externum, etc., by no 

 means imply that a luminous sensation has been called forth. In fact 

 we have independent evidence that a sensation is not evoked by such 

 a reflex. Professor Munk insists that the decerebrated dogs were 

 blind — totally blind. 



The hearing of these dogs is next considered and it is urged that 

 their actions do not evidence that they heard the fog horns, etc.; but 

 that these harsh sounds produced mere reflexes arising from a sense of 

 unintelligent discomfort. Such sounds are capable of evoking common 

 reflexes, even though they were not heard and though they called 

 forth neither pleasure nor pain. The motions of the dogs were not 

 those of attention, but those of common reflexes. Moreover, they 

 obey the laws of the latter, not those of the former. The conclusion, 

 then, is that what Professor Goltz saw as a result of the noises has 

 nothing whatever to do with hearing and the decerebrated dog was 

 quite deaf. The whining, barking, howling, etc. observed, do not 

 contradict Munk's observation that dogs deprived of the " Hors- 

 phaeren " are both deaf and dumb, for these sounds were made only 

 upon the immediate application of a strong stimulus ; never from 

 psychic stimuli like presence of food or desire for mates. Neither 

 the phenomena observed by Goltz nor Munk are due to a general 

 weakening of mental power, but both to an actual psychic deafness. 



The " tactile sense" of Goltz, too, is merely an excitation of the 

 common feelings which produces common reflexes. It must be re- 

 membered that sensations of contact or pressure are indissolubly 

 linked to local signs. These produce in the aggregate common feel- 

 ings which in turn, are associated with common reflexes, each of 

 which arises only upon the occasion of mechanical irritation of a par- 

 ticular cuticular area. Now in Professor Goltz' dogs the most char- 

 acteristic feature of tactile sensations — localization — is lacking by his 

 own confession. The tactile hyperesthesia observed in these dogs is 

 quite incomprehensible on his supposition of a general lowering of 

 the psychic faculties, but not an abolition of them ; but from Profes- 

 sor Munk's standpoint it would be quite natural to suppose that the 

 common feelings, would be intensified by the loss of tactile sensations. 

 This is in accord with the known facts of hyperexcitability of lower 

 centres after their separation from the inhibitory higher centres. 



Such is Professor Munk's commentary upon Professor Goltz' ob- 



