24 ARON. 



Both animals had been given an excess of food to enable them to grow 

 to the greatest possible extent and therefore the relative amounts of fat 

 and flesh, as compared with the skeletons, were larger than in the case of 

 the control dogs C and D which had been killed more than a year before; 

 the bones in both animals were relatively lighter. However, it will 

 be seen that the bones of dog A, in which the growth was suppressed in 

 the first period of the experiment, weighed considerably less in proportion 

 to the total live weight than was the case with the normal control 

 animal B, this being the result of the excessive feeding of A. Plate IV 

 shows several bones of both A and B, and demonstrates that the various 

 bones of A had not reached the dimensions of those of its normal brother, 

 in spite of the fact that for five months it had been given a more than 

 ample diet. 



DISCUSSION OF EXPERIMENTS. 



INFLTJETs'CE OF A RESTRICTED DIET ON THE WEIGHT AND APPEARANCE OF 



GROWING DOGS. 



In six animals (II, III, VI, XI, XIV, A) an attempt was made to 

 suppress growth by restriction of food. All these animals were far behind 

 their normal brothers (I, IV, V, VIII, XII; B and C, respectively) in 

 weight. In spite of the restricted diet there was a slight increase in 

 weight in the first group. The weight of dog number VI of the second set 

 increased but very slightly in the first period, after that it remained 

 constant, and decreased only at the end of the experiment. Number XI 

 of the third set also lost but very little; the weight of number XIV re- 

 mained practically constant. The weight of dog A of the fourth group 

 remained nearly the same for ten months (fortieth to three hundred 

 and fiftieth day), increasing but very slightl}^ The weight in all these 

 dogs was so nearly constant that we are justified in so regarding it, the 

 increase or decrease amounting to a few grams only. Did a cessation of 

 growth take place with this constancy in weight ? By no means ! We 

 have already seen that in spite of the constancy of weight all the dogs in- 

 creased in length and height. At the same time the animals became 

 leaner, fat and muscles diminished, the well-rounded form of the bod}^ 

 disappeared, and the bones became visible in outline directly under the 

 skin. The dogs when in this condition were by no means weak. They 

 jumped about and were often more active than their nonnal brothers, but 

 the latter had to carry nearly three times as much live weight. 



This stage, in which the dogs grew leaner but longer and taller, while 

 the weight was practically constant, lasted for from three to five months, 

 varying somewhat with the degi'ee of restriction of the food. If now 

 the restricted diet was continued, when the animals were emaciated to 

 an extreme 'degree, they died of inanition following a slight loss of 



