226 PHYSIOLOGY AT THE FARM. 



duces more compounds of hydrogen and carbon than are 

 required for immediate use, the excess of these elements is 

 stored up within the body in the form of fat, to be ready for 

 use when the expenditure exceeds the supply at the moment. 

 When the body is subjected to active muscular exertion, under 

 which respiration is always augmented, the accumulation of 

 fat is prevented by the increase in the consumption of the 

 fuel employed. But when the supply of calorific matter for 

 respiration is lessened by a deficiency of food, or by failure in 

 the digestive process, there is a reserve within the body in the 

 fat which has become accumulated ; and in starvation, the fat 

 is the first solid which disappears. 



In hybernating animals, such as the hedgehog, the fat ac- 

 cumulated before winter sets in, both maintains the temperature 

 during the suspension of nutrition, while their winter sleep 

 lasts, and affords a temporary supply of material for eremacau- 

 sis in spring, when the respiration first recovers its activity. 



It has been calculated that the mean proportion of fat in 

 the human body is about one-twentieth of its weight. Here, 

 however, the greatest differences must prevail. The propor- 

 tion for the most part is greatest in the middle period of life, 

 while it declines as old age advances. In man, rich food, tran- 

 quillity of mind and body, and an excess of sleep, favour the 

 growth of fat. In females and in eunuchs the tendency to the 

 production of fat appears to be in higher measure. In domesti- 

 cated animals a corresponding state of the fact is observed. 



Areolar, Cellular, or Connective Tissue. The cellular tissue, 

 known by a multitude of names, is the soft filamentous sub- 

 stance, often of a white fleecy aspect, by which the various 

 other textures of the living body are connected together. The 

 mode of representing the extent of this tissue common with the 

 old authorities was to say that if all the other tissues were 

 annihilated, this would still preserve the form of the body. 



