TWO CILIATA OF GREAT SALT LAKE. 28 1 



that of this ciliate, lost its identity two minutes after being swal- 

 lowed. At one time an amoeba was swallowed that occupied 

 fully one-half of the protozoan's body. It may feed for several 

 hours, then quiet down, contract into a short ellipsoid during 

 which time it extends at intervals the oesophagus rods. After 

 about one hour of this procedure it elongates and swims away, 

 continuing again the process of feeding. 



It is an active swimmer. Reproduction is brought about in a 

 short period, by longitudinal fission. Cysts were observed and 

 the contained individuals were found to be sensitive to light, 

 a fact discussed in connection with symbiotic alga. 



CONCLUSIONS. 



1. Though the number of animal and plant species reported 

 from Great Salt Lake is only seventeen, evidence goes to show 

 that this number will at least be doubled. 



2. The milky cultures are the result of an unbalanced animal 

 and plant relationship. 



3. Continuous dilution was an advantage in that it did not 

 destroy delicate forms, and the offspring of only a few individuals 

 were studied. 



4. The two ciliates responded to dilution of the medium by 

 increased size, increased activity, shortening of the feelinp" cirri, 

 more active physiological and reproductive processes, and more 

 flexible and contractile bodies. 



5. These protozoans contain chlorophyll, probably in the 

 form of a symbiotic alga. 



6. The results of the foregoing experiments show that these 

 ciliates are plastic and capable of adaptation. 



7. It is believed from the foregoing that by slowing down the 

 rate of dilution, some of these Great Salt Lake forms may be 

 transformed into fresh water animals. 



8. Most cordial thanks are due Professor Newton Miller, who 

 followed the work with interest and gave many helpful criticisms. 



BIBLIOGRAPHY. 

 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, Washington, 

 D. C., 1845. 



