24 ALBERT C. JENSEN. 



The stench is due primarily to decaying vegetable matter. 

 Vessels placed in the laboratory containing plant material from 

 the lake gave off the characteristic lake odor. Further the odor 

 was present at the lake as early as the last of March, before the 

 appearance of Artemia. Again the proportion of the phyllopods 

 to the plant material is so small as to make the brine shrimp an 

 insignificant factor in the odor production. 



CONCLUSIONS. 



Winter eggs of Artemia kept in normal lake water at room 

 temperature (about 20 degrees centigrade) for a period of two 

 months did not hatch earlier than those in the lake. 



The embryo of Artemia develops into a free-swimming nau- 

 plius, much unlike the adult, which passes through a series of 

 stages before reaching maturity. 



Artemia reproduces by means of fertilized eggs and also 

 parthenogenetically. 



Eggs will hatch during the winter as well as spring and summer 

 in dilute lake water or in fresh water at a temperature as low as 

 20 degrees centigrade. My experiments show also that eggs 

 will not hatch in solutions concentrated to near the saturation 

 point. 



Artemia passes the winter months in the egg stage. 



Artemia will not live in fresh \vater, but will in a dilution of 

 the lake water having a specific gravity of 1.027. 



Lake water diluted to a specific gravity of 1.044 to 1.027 is 

 most favorable for the development of Artemia. 



I take this opportunity to heartily thank Dr. Newton Miller 

 for his assistance in this work. 



REFERENCES 



Fremont, John C. 



'43 Report of the Exploring Expedition to the Rocky Mountains in the Year 

 1842, and to Oregon and North California in the Years 1843-4. Washing- 

 ton, D. C., 1845. 

 Verrill, A. E. 



'69 Twelfth Annual Report U. S. Geological and Geographical Survey of the 

 Territories of Wyoming and Idaho, 1878, Part i, page 330. Washington. 

 D C. 



