408 



University of California Publications in Zoology [Vol. 20 



D. CONCLUSIONS 



1. Routine examination of normal rodent faeces for discovering 

 intestinal Protozoa is a tedious and unreliable method. 



2. Stale bread soaked in a saturated solution of magnesium sul- 

 phate in water is a convenient purgative to administer to rats. 



3. Examination on two consecutive days of the faeces from 128 

 purged rats, prociired by this method, after which the rats were 

 autopsied and the intestinal contents examined, showed that this is a 

 relatively safe method for the detection of amoebic and trichomonad 

 infections in rats. 



4. Young rats show the greatest susceptibility to infection and 

 are the most satisfactory for infection experiments. 



Zoological Laboratory, 



tjNn'ERSITY OF CALIFORNIA. 



Transmitted July 11, 192S. 



E. LITERATURE CITED 

 Brug, S. L. 



1919. De entamoeben van de rat. Geneesk. Tijd. Nederl. Indie, 59, 1-15, 



pis. 1-2. 



DOBELL, C. 



1917. Eeports upon investigation in the United Kingdom of dysentery eases 

 received from the Eastern Mediterranean. I. Amoebic dysentery 

 and the protozoological investigation of cases and carriers. [Brit 

 ish] Medical Research Committee, Special Report Series, No. 4 (Lon 

 don, Joseph Causton and Sons, Ltd.), pp. 1-85. 

 DoBELL, C, and O'Connor, F. W. 



1921. The intestinal Protozoa of man (London, John Bale, Sons and Daniels 

 son, Ltd.), v + 211 pp., pis. 1-8, 2 figs, in text. 

 Hegneb, B. W. 



1923. The effects of changes in diet on the incidence, distribution and num 

 bers of certain intestinal Protozoa of rats. Am. Jour. Hyg., 3, 

 180-200, pi. 4. 

 Kessel, J. F. 



1923a. Experimental infection of rats and mice with the common intestinal 

 amoebae of man. Univ. Calif. Publ. Zool., 20, 409^30, pis. 38-39 

 1923b. The distinguishing characteristics of the parasitic amoebae of culture 

 rats and mice. Ibid. {In press.) 

 KoFoiD, C. A., and Swezy, O. 



1920. On the prevalence of carriers of Endamoeia dysenteriae among sol 



diers returning from overseas service. New Orleans Med. and Surg. 

 Jour., 73, 4-11. 

 KoFoiD, C. A., Kornhauser, S. I., and Swezy, O. 



1919. Intestinal parasites in overseas and home service troops of the U. S. 

 Army. Jour. Am. Med. Assoc, 72, 1721-1724. 

 Wenyon, C. M. 



1907. Observations on the Protozoa in the intestine of mice. Arch. f. Prot 

 Suppl. 1, 169-201, pis. 10-12. 



