416 



H. R. HULPIEU AND D. L. HOPKINS. 



these cultures and the one mentioned in the preceding paragraph, 

 were thoroughly examined at least twenty-five times during the 

 two months growth period, and no large amoebae could be dis- 



FIG. 2. Camera lucida drawings of a small amoeba just before division (i) and 

 (2) and immediately after division (30) and (36). 



covered until the end of two months as stated. It is, therefore, 

 evident that even one large amoeba could not have remained in the 

 large form unobserved during the growth period of nearly two 

 months. 



It is evident that the small forms develop into large ones and 

 that as they do so they divide from time to time. 



SUMMARY. 



Individuals of Amoeba proteus sometimes break up into from 

 100 to 300 amoeboid forms. These amoeboid forms gradually 

 become larger until at the end of about two months they are as 

 large as the original specimens. During the increase in size 

 division occurs from time to time. 



LITERATURE CITED. 

 Calkins, G. N. 



'05 Evidences of a Sexual Cycle in the Life History of Amceba proteus. Archiv. 



f. Protistenk. Bd. 5, pp. 1-16. 



'07 The Fertilization of Amoeba proteus. BIOL. BULL., Vol. 13, pp. 219-230. 

 Carter, H. J. 



'56 Notes on Fresh Water Infusoria of the Island of Bombay. Ann. and Mag. 



of Nat. Hist., S. 2, Vol. 18, pp. 115-132. 

 '63 On Amoeba princeps and its Reproductive Cells. Ann. and Mag. of Nat. 



Hist., S. 3, Vol. 12, pp. 30-51. 



