THE DIFFERENT FORMS OF OBESITY 571 



tents of an individual, but must rely on coarse, insufficient estimations. 

 The investigations up to the present on the fasting and rest values of corpu- 

 lent individuals (v. Noorden, Thiele and Nehring, Stuve, Magnus-Levy, 

 Rubner, Jacquet and Svenson, Salomon, Reach, Staehelin, and v. Bergmann) 

 have been subjected to an analytical criticism by v. Noorden; the calculation 

 of the exchange per kilo of body weight, must, as already mentioned, be 



C>2 consumption 

 rejected as of no use. The calculation of the quotient 



body height 



shows in corpulent individuals higher values sooner than in normal indi- 

 viduals. This is perhaps due to the fact that in heavy accumulations of fat 

 the work of the heart and of the respiratory muscles is perhaps made more 

 difficult, v. Noorden arrived at the result that the estimation of the respira- 

 tory exchange at rest has up to the present furnished no sure decision in this 

 question. This is true apparently of the estimations up to the present of the 

 factors influencing the exogenous respiration gaseous exchange. The 

 opinion has been held that in the corpulent the ingestion of food should 

 call forth a slighter increase of the exchange. Herein lies a tendency to 

 saving. The experiments that have been made up to the present, however, 

 do not bear strict criticism. Up to the present only the determination of 

 the calorie requirements has led to reliable results in some cases. The supply 

 of heat was estimated in a very careful manner and for a long period, and it 

 was determined that corpulent persons either take on fat or do not lose it 

 under conditions under which normal persons either would not become corpu- 

 lent or would lose in body weight. In this method care should be taken that 

 exogenous factors are not allowed to take a part. The corpulent individual, 

 to whom every movement is attended with exertion and is disagreeable, 

 has often learned to get along with the minimum of movement, otherwise 

 he sits and stands as a normal individual. To this must be added also the 

 phlegm of such individuals. These methods can thus furnish a certain 

 conclusion as to the diminution of the fundamental exchange, if extremely 

 low values are found. This is actually so in the cases reported. Such cases 

 are, however, as v. Noorden has pointed out, quite rare. 



We must now consider the question as to whether a diminution in the 

 fundamental exchange characterizes endogenous obesity, and whether this is 

 necessary for the assumption of a case as such. In a typical myxedema it is 

 true that simultaneously with the reduction in the fundamental exchange 

 there occurs an increase of the body weight, but this does not always progress 

 to obesity. It is much more probable that the increase in weight can de- 

 pend solely or in great part on the accumulation of myxedematous tis- 

 sue and the water accumulation. In normal grown individuals the ingestion 

 of food rises or falls with the greater or lesser need for it. The body weight, 

 .apart from slight variations, often remains the same for years at a time. 

 This depends on a fine regulatory mechanism that as yet has not been investi- 



