240 W. J. M. SCOTT 



new and delicate cytoplasmic criterion of cell activity which is 

 indeed supported by recent observations. Thus Dubreuil ('13, 

 p. 138) found that they increased definitely in inflammatory 

 processes just as Romeis ('13, p. 12) observed an increase in 

 regenerating tissues. Homans ('15, p. 12) was able to relate 

 them to an increased demand upon the activity of islet cells of 

 the pancreas in experimetal diabetes; and Goetsch ('16) dis- 

 covered that an increase in their numbers was correlated with 

 an increase in the activity of the thyroid epithelium and with 

 the severity of the clinical symptoms of hyperthyroidism, in man. 



MATERIAL AND METHODS 



White mice were used. The phosphorus was administered 

 by subcutaneous injections of an olive oil solution. In the first 

 experiments the concentration of phosphorus in the solution was 

 0.0125 per cent which was later increased to 0.05 per cent. 

 Several injections of various amounts of 0.1 to 0.2 cc. were given 

 to each mouse at intervals of a day or more — for a longer or a 

 shorter time depending upon whether it was desired to bring 

 about a severe or a slight reaction. The animals usually showed 

 pronounced symptoms within a few days, so that the intoxi- 

 cations must be regarded as rather acute. 



Animals in the desired stage of poisoning were killed with 

 chloroform. Pieces of the pancreas were first removed to 

 physiological salt solution. A part of it was then examined in 

 the fresh condition. Other portions were vitally stained by 

 immersion in solutions of janus green as well as with the other 

 dyes in general use. Pieces were also fixed in a variety of mix- 

 tures, chief among which may be mentioned formalin and bi- 

 chromate (Regaud) and acetic osmic bichromate (Bensley) for 

 mitochondria; osmic acid, commercial formalin, neutral and 

 alkaline formalin, among others, for the demonstration of fat 

 and other substances. Many different methods of staining 

 were employed; the acid fuchsin methyl green and the iron 

 hematoxylin methods for mitochondria; Sudan III, Scharlach 

 R, Mallory's stain, hematoxyhn and eosin and a variety of 

 others were used. 



