26 CHARLES F. W. MC CLURE 



to gain in weight, and continue to do so as long as the disease 

 is progressive. This continuous gain indicates that more 

 water is being transported through the integument into the 

 subcutaneous lymph sinuses than is simultaneously being ex- 

 creted by the kidneys, and leads to the gradual production 

 of a localized or generalized oedema, subcutaneous as well 

 as intracellular (interstitial?) in character. 



In table 6 is shown a number of experiments which bear out 

 the above statement that if frogs with well-defined symptoms 

 of red-leg disease remain in water, they gain weight continu- 

 ously. As the disease progresses, it will be observed that, in 

 course of time, the frogs become weak and sluggish and react 

 slowly to stimuli. This condition is succeeded by coma and 

 death follows. The disease is usually fatal at room tempera- 

 ture; Emerson and Norris state, however, that at low tem- 

 peratures its progress may be arrested. 



In experiment 161 (table 6) an apparently healthy frog, 

 showing no extern? 1 symptoms of red-leg, and selected for 

 the purpose of studying its normal behavior, was observed 

 to lose weight continuously during a period of about four 

 hours, after being transferred from water at room tempera- 

 ture to water at 33 °C. Up to this point, the behavior of the 

 frog was normal in respect to the balance that had been 

 established between the incoming and outgoing flow of water. 

 After the fourth hour, however, external symptoms of red- 

 leg made their appearance, and after this time the weight of 

 the frog increased continuously. 



The selection for experiment of frogs which one would 

 commonly regard as healthy and free from red-leg has proved 

 in some cases a difficult matter. While the character of its 

 desiccation recovery curves (curves 1, 2, and 3 in fig. 1) and 

 its behavior when placed in water generally indicate whether 

 a frog is in healthy condition, the unexpected appearance of 

 red-leg in frogs thai in these respects give normal reactions 

 is by no means an uncommon occurrence in the experience of 

 the writer. An example of this is well illustrated by curve 6 

 in figure 1. The frog from which, this curve was obtained 



