2O8 LOUISE H. GREGORY. 



continued when the series is returned to the normal environment. 

 Beef seems to be an immediate stimulant if the protoplasm is 

 mature, and a delayed stimulant if the series is young or old, the 

 effect being seen only after transference to normal hay-flour 

 medium. 



BARNARD COLLEGE, 



COLUMBIA UNIVERSITY, 

 NEW YORK CITY. 



REFERENCES. 



1. Woodruff, L. L. 



'05 Jour. Exp. Zoology, Vol. 2, No. 4, p. 585. 



2. Calkins, G. N. 



'19 Jour. Exp. Zoology, Vol. 29, No. 2, p. 121. 



3. Woodruff and Baitsell. 



'ii Jour. Exp. Zool., Vol. n, p. 135. 



