310 THE CAUSE OF HEALING 



0.007 gramme of atropine sulphate to the 10 cc. of 

 jelly which has 10 units of alkali, divisions in lympho- 

 cytes can be induced if the jelly also contains no more 

 than 0.01 gramme of dried suprarenal extract. Once 

 more we tried to induce divisions with the alkaloid by 

 itself, but failed; and yet it augmented the action of 

 the extract five-fold. In addition to this augmentation 

 it induced asymmetrical mitoses (fig. 105). 



To recapitulate: Extract of suprarenal gland of 

 certain strength will induce by itself mitotic divisions 

 in lymphocytes; and if more of it is made to diffuse 

 into cells, it will also cause leucocytes to divide. If a 

 lower concentration is tried, however, it will not induce 

 divisions in the experimental ten minutes unless (1) it 

 has become putrid, (2) its action is augmented by 

 atropine. In both the latter circumstances asym- 

 metrical mitosis may be seen. 



Other extracts of dead tissues were then tried; but 

 they would not, by themselves, induce divisions in the 

 experimental ten minutes. Realising that this might 

 be due to the detrimental experimental conditions 

 (corollary 2), we tried them again with atropine to 

 augment their action. Now, as surmised, all the 

 extracts of dead tissues which we tried induced 

 divisions in lymphocytes on the microscope slide. To- 

 induce divisions in polymorphonuclear leucocytes with 

 them is much more difficult, as atropine does not appear 

 to augment their action so much with these cells. 



The following table gives the strengths of the 

 various extracts which, with 1 cc. of alkali (10 units) 

 and 0.007 gramme of atropine sulphate, will induce 



