CHAPTER XVIII 

 OUTPOSTS OF THE INTELLIGENCE SERVICE 



(a) GENERAL AND INTRA-COMMUNAL RECEPTORS 



" By mine eye, I do not know that I see, or by mine ear that I hear, but by 

 my common sense who judge th of sound and colours." BURTON. 



THE Cabinet which controls a nation has to set up machinery 

 to provide itself with two different kinds of intelligence. First 

 it needs to know how its orders are being carried out by the 

 civilian population as well as by the military. The internal or 

 interoceptive intelligence staff is distributed among the factory 

 workers, along lines of transport and in the various effective units 

 of the army. Their duty is to report on the conditions in their 

 sector. Before a shortage of raw material has become so marked 

 as to cause an outcry from, or mayhap, a strike of some part of 

 the population, the outposts of the intelligence staff should have 

 their report " on the wires." Very little is known of how this 

 work is carried out. It is mere guesswork to say that slight 

 alterations in the physico-chemical condition of the material 

 surrounding a nerve-ending is sufficient to cause stimulation of 

 the nerve. The other intelligence staff operates on matters 

 outside the organism. They are exteroceptors. 



Sherrington divides interoceptors into two groups : 



1. General, which have to do with sensations of hunger or 

 thirst, nausea, respiratory and circulatory sensations, sexual 

 sensations, visceral pain, etc. 



2. Special consists of end organs for taste and smell. These 

 are distinctly chemical in their actions and are the chief extero- 

 ceptors in many animals (see later). 



To these fall to be added a group with a double function : 



3. The somatic proprioceptors, which are situated in the muscles, 

 tendons and joints, and are concerned with the production of 

 the muscle sense. To this group also belong the organs which 

 have to do with the sensations of equilibrium. Not only have 



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