432 Gary N. Calkins. 



(made fresh), while the other four were placed in hay infusion 

 without the salt. Of the former set, each individual divided once 

 in 48 hours, and of the latter set, one died, two divided once, and 

 one divided twice in the same period. The regular control series 

 did not divide at all during this time. Both sets were placed in 

 hay infusion on the fourth day and neither set continued to live, 

 all died before the sixth of November. Another set of four in- 

 dividuals were treated with the salt every day for the same period. 

 After the first 24 hours none had divided; after the second 24 

 hours each one had divided once. This was November 2. On 

 the 4th all had divided twice, on the 6th only one had divided 

 again, on the 7th another one had divided, on the 8th none had 

 divided again, on the 9th one died, while the rest did not divide, 

 on the loth two others died, and the remaining one was placed in 

 the usual hay infusion without the salt, having been treated 

 daily for ten days with it. It did not divide again until the i8th, 

 and finally died out on the 21st. Others, however, that had been 

 treated, and had been placed earlier in hay, continued to live and 

 supplied the regular lines of the experiment. The use of the 

 KCN therefore can be said to have been successful to a limited 

 extent, and, possibly, to have prevented an earlier extinction of 

 the race. The effect on the curve of the life cycle is shown by the 

 temporary rise during the last period in October and the first 

 period in November. 



d. KOH. This was tried only once with four individuals on 

 the 28th of October. ^^^-^ i part to 4 was used for 30 minutes. 

 On the first of December two had died and one had divided once. 

 None divided again and all of the individuals experimented with 

 died before the fourth of November. 



B. Sodium Salts. 



a. Dibasic Sodium Phosphate. Three individuals, Al, A3 

 and A4 were placed for 30 minutes in ^S^^ NajHPO^. All 

 died without dividing by the 27th. The experiment was not 

 repeated. 



b. Sodium Tartrate. July 10 two individuals were placed for 

 30 minutes in -^^ sodium tartrate, one drop to five of hay infusion. 



