300 THE CAUSE OF HEALING 



no doubt about it this extract did actually induce 

 mitotic figures in lymphocytes in the experimental 

 ten minutes (figs. 97, 98). No azur stain, atropine, or 

 other "augmenter" was added; the decomposed 

 suprarenal extract induced mitosis by itself. 



Of course we thought at first that this result 

 was due to the concentration of the extract; but 

 this thought was soon dispelled by trying some of 

 the other tubes which had been kept alongside of 

 the ones w r hich had so often been examined, the 

 contents of which had decomposed. The sterile 

 extract contained in these tubes would not induce 

 divisions by themselves. Moreover, at the temperature 

 of the laboratory, since they w r ere kept in plugged 

 tubes, the extracts did not evaporate very fast, and 

 it was appreciated that they could not be so very 

 concentrated. Some of the effective putrid extract, 

 therefore, had water added to it, so that it was again 

 made up to its original strength of 100 per cent. It 

 w r as then made up in a jelly as before, and to our 

 astonishment again it induced divisions in lympho- 

 cytes; and what is more important, it induced the 

 asymmetrical one-sided mitosis in many instances 

 (fig. 99). 



A series of control experiments \vas then made. 

 .Jellies which contained only the salts sodium citrate, 

 sodium chloride, and the 1 cc. of alkali were first 

 tried, and no divisions could be seen. Then yet 

 another series of experiments with fresh extract of 

 suprarenal gland w r as made, once more without re- 

 sult, and so it w r as ultimately proved that it was 



