1056 Influence of circumstances on the Actions of Animals. 
changes of conditions acting in the organs of some one individual 
during its life as the sole result of a great change in the habits 
peculiar to the individuals of its species. The following remark- 
able fact fully proves the influence of habits on the condition of 
organs, and how continued changes in the habits of an individual 
bring changes in the state of the organs which enter into action 
during the exercise of these habits. M. Tenon, member of the 
Institute, has communicated to the Classe des Sciences, that having 
examined the intestinal canal of many men who haye been ardent 
drinkers during a great part of their life, has constantly found it 
shortened to an extraordinary degree compared with the same organ 
of all those who had not a like habit. It isknown that great drinkers 
or those who are given to drunkenness, take very little solid food; 
that they eat almost nothing, and that the drink which they take 
in abundance and frequently, suffices for their nourishment. Since 
fluid aliment, and, above all, spiritous drinks, do not remain long 
either in the stomach or in the intestines, the stomach and the 
rest of the intestinal canal loses in drunkards the habit of distention. 
So also in persons of sedentary habits, and constantly applied to 
mental work, who habituate themselves to take very little nourish- 
ment. Gradually, in time, their stomachs contract, and their intes- 
tines become shortened. It is not a question here of shrinking 
and shortening produced by a contraction of parts which would 
permit of ordinary extension, if in place of a maintained vacancy 
_ these viscera should become filled ; but it is a question of real shrinks 
ing and considerable shortening, so that these organs would rather 
burst than yield suddenly to the causes which would produce 
ordinary distension. Circumstances of age being entirely equal, 
_ compare a man who habitually devotes himself to studies and mental 
_ work, who has rendered. his digestion sluggish, has contracted 
_ the habit of eating very little, with another who habitually and 
often takes much exercise and eats well; the stomach of the first 
would have reduced functions, and a very small quantity of 
aliment would fill it, whilst that of the second would be preser x 
and even increased. See then an organ greatly modified in 1ts 
dimensions and functions by the one cause of a change in its habits 
during the life of the individual. The frequent employment of 
an organ in becoming adapted to its habits, augments the function 
