72 THE WORK OF THE DIGESTIVE GLANDS. 



there is even a quantitative relationship between this effect and that of 

 the sham feeding. 



Here i.s an experiment of Professor Ssanozki, in which the secretory 

 effect of the mere tempting of the animal with the sight of food is com 

 pared with that of sham feeding. A few threads of alkaline mucus had 

 just escaped from the stomach, and then the excitation of the dog with 

 flesh was begun. After six minutes the secretion commenced and 

 continued as follows : 



Duration of the flow. Quantity of the juice. 



8 minutes ..... 1" c.c. 



4 10 



4 ., 10 



10 10 



1<> ., 10 



8 . 10 



8 10 



1!) .. 10 



1!) 3 



Then followed a sham feeding for six minutes. 



17 minutes ..... 10 c.c. 

 ' 10 



8 10 



Ib is clear that in this case the tempting instead of being less 

 effective than the sham feeding, on the contrary excelled it. 



Consequently, the observation of Bidder and Schmidt was perfectly 

 correct. It c innot, however, be said that it received general recognition 

 in physiology, or that it was sufficiently appreciated. There are authors 

 who could never convince themselves of its reality, and in many physio- 

 logical text-books it is not once mentioned. By way of explanation, we 

 shall now consider how this matter must be dealt with by those who 

 wish to observe the effect. Ib is only under certain conditions that it 

 can be seen. Firstly, the animal must be healthy and vigorous, ib must 

 have a perfectly uninjured gastric mucous membrane, and this from 

 the description, in the case of many authors who obtained a negative 

 result, was not the case. Secondly, the success of the experiment, as 

 stated above, is dependent upon the intensity of the desire for eating, 

 and this, again, is dependent upon how freely and how long beforehand 

 the dog had eaten, and also upon what it is tempted with, whether with 

 a dish that excites its desire or leaves its interest una wakened. It is 

 known that dogs have very different tahtes, just as men have. Thirdly, 

 one may find among the dogs, positively careless indifferent creatures, 

 incapable of being perturbed in this way by anything which has not 



