348 LEON AUGUSTUS HAUSMAN. 



then proceeded to take on a form similar to the adult proteus. 

 Such individuals were isolated, and soon grew in size to adult 

 form, and were, apparently, Amceba proteus. Fission was ob- 

 served to take place among some of these, but no further repro- 

 ductive activities were noted. The entire sequence of events 

 which have been enumerated took place within three months, 

 the cultures being kept in the glass oven already described, at an 

 average temperature of 80 degrees Fahr. 



Some of the individuals of nearly adult proportions developed 

 long, whip-like, and flexible pseudopodia, often more like long 

 threads (Fig. 16). These were clear, even the stouter ones being 

 devoid of granules. Gruber ('n) reported a similar type of 

 pseudopodium (there was but one in this case) which was sent 

 out from the body and moved about as if an organ of exploration. 



Some of the most bizarre forms occur during the transition 

 period between the smallest form and the Dactylosphcerium stage. 

 Fig. 14 represents forms, all but one of which were taken from 

 the same slide. 



In Fig. 1 8 an attempt has been made to group the various 

 forms observed in a tentative cycle of development. The nine 

 arbitrary stages appear to occur in the following order: 



1. Adult stage. 



2. Division of the nucleus, and migration of the nuclei to the 



posterior extremity of the body. 



3. Escape of apseudopodiospores. 



4. Amceba guttula stage. 



5. Small Amceba proteus stage. 



6. Amceba radiosa stage. 



7. Dactylosphcerium radiosum stage. 



8. Resumption of amoeboid form. 



9. Growth to adult size. 



BIBLIOGRAPHY. 

 Biitschli, O. 



'80 Protozoa, in Bronn, H. G. Klassen und Ordnungen des Thier Reichs, 



parts 8 and 9. 

 Calkins, G. N. 



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



fur Protistenkunde, Vol. 5, p. i. 

 '07 Fertilization of Amtzba proteus. BIOL. BULL., Woods Hole, Mass., Vol. 



13. P- 219. 



