EFFECTS OF CHANGES IX MEDIUM. 



2O1 



all of the following experiments with beef extract. A .05 per 

 cent, solution of beef extract made up with Great Bear Spring 

 w.iu-r and a 24-hour-old solution of flour water of the same 

 5tr< tigth as in the normal hay-flour medium of Calkins, were used 

 in equal amounts. This resulting medium \\ - - 'Union of the 

 mo-t favorable U-ef strength and exactly similar to the normal 

 medium except that the beef solution had been .-ub-iituted for 

 the hay. 



In conduct- experiments one individual \\a- taken from 



earh of the ii\e lines of the control serie- and placed in the beef 

 Hour nedium. lioth series were kept under the >ame condition- 

 of li-ht and temperature. They were transfered tfn>h medium 

 at the same times and differed only in the hay or U if element of 

 the medium. As in all similar experiment- the rate of di\i-ion 

 \\.i- taken ,i- the indication of the vitality of the protoplasm. 



DISCUSSION OF EXPFRIMI M-. 

 ,' Response of Young Protopla 



I Me I -hows the results of feeding very immature -i-rie- u ith 

 the beef-llour medium. Six young series of live line- each v 

 te-ied for their reaction to the substitution \ U-ef extracl for the 

 ha\ in normal medium and in every case tin : a lo\\-rii'. 



the \italit\- indicated by the slowing of the di\i-ion rate. The 

 amount ot the depression \\iriecl from 1.8 i ^.t> di\i-ion- in ten 

 da\- t' i line of the series. Ever>' \-oiin;< line re-ponded in 



tin- -ame \\a\- indication that in this period whieh in tin 

 extended from the 5th to the 4oth generation, the protop1.,Mii 

 was in i i ondition in which the normal metabolic pmcr - \\err 

 ea-iiy and immediatel\ - upset and the \'italit\- lowered. 



TAHI.I-: I. 





! I MM \ I I kin'. 



