Phylum V 



Plathelminthes, Class Turbellaria 



Order rhabdocoelida, Family catenulidae 



CULTURE OF STENOSTOMUM OESOPHAGIUM 



Margaret Hess, Judson College, Marion, Alabama 



CULTURE medium for Stenostomum oesophagium is prepared in the 

 following manner: 



Boil 250 cc. of water with 8 to 10 grains of wheat for one minute; 

 allow to stand exposed to the air for 24 hours; remove about two-thirds 

 of the wheat grains and inoculate with a mixed laboratory culture of 

 Protozoa. 



Introduce Stenostomum oesophagium into this culture 24 hours or 

 more after the addition of the Protozoa. The presence of other Turbel- 

 laria, oligochaetes, and small Crustacea has no harmful effect on Sten- 

 ostomum oesophagium. 



Varying temperatures have little effect on Stenostomum oesophagium, 

 although room temperature has been found the most satisfactory for 

 rapid growth and multiplication. Likewise they are able to withstand 

 variations in hydrogen-ion concentration. The best cultures show a pH 

 range of 5.8 to 7.6.* 



CULTIVATION OF STENOSTOMUM INCAUDATUM** 



T. M. Sonneborn, Johns Hopkins University 



THIS turbellarian may readily be cultivated in mass or in isolation 

 pedigree cultures if fed copious supplies of the ciliate Protozoan, Col- 

 pidium campylum. The basic medium is prepared by boiling for 10 

 minutes 15 grams of whole rye grains in one liter of spring water. This 

 infusion is filtered while hot, cooled, inoculated with 1 cc. of a similar 



♦Editor's Note: Concerning two other species of Stenostomum, Jeanette Seeds Carter 

 states (/. Exper. Zool. 65:159, 1933) that S. grandc is naturally cannibalistic and that in 

 5. tenuicauda cannibalism is not a normal phenomenon. J. G. N. 



** Condensed by the author from: Genetic studies on Stenostomum incaudatum {nov. 

 spec). I. The nature and origin of differences among individuals formed during vegetative 

 reproduction. J. Exper. Zool. 57:57, 1930. (See pp. 62 and 63.) 



148 



