390 Journal of Agricultural Research voi. xxnNo, 8. 



four times in succession to fresh salt solution. In this manner the sur- 

 face of the worms was freed from adhering intestinal material. In the 

 case of salt-solution extracts that were allowed to remain at room tem- 

 perature or in an incubator for several hours or for a few days, a pre- 

 servative, usually a few drops of chloroform, was added to the extract 

 to inhibit bacterial growth. 



Specimens were dried as follows: After having been washed a number 

 of times in physiological salt solution, the surface of the worms was 

 dried with filter paper. The specimens were then placed in a single 

 layer in a glass dish and allowed to dry either at room temperature in 

 an incubator or in vacuum over sulphuric acid. Small worms dry in a 

 few hours, even at room temperature, and become sufficiently crisp to 

 be pulverized. Larger specimens dry more slowly and are usually crisp 

 in about 48 hours. The dried material was triturated in a mortar and 

 stored in bottles, usually in a dark place. 



Special points in technic are covered in connection with the different 

 series of experiments and are not taken up in this connection. 



As used in this paper, the terms physiological salt solution and salt 

 solution refer to an 0.85 per cent solution of sodium chlorid in distilled 

 water. 



Controls on all samples of blood corpuscles used in the experimental 

 work described in the following pages were maintained in connection 

 with each experiment or series of experiments. 



IV. EXPERIMENTS WITH HEMOLYTIC EXTRACTS OF ASCARIS I.UM- 



BRICOIDES 



I. METHOD OP OBTAINING FI,UID FROM WORMS 



Body fluids and extracts were obtained from specimens of Ascaris 

 lumbricoides from swine. A supply of these parasites is available in 

 abattoirs during all seasons of the year. 



The fluid which is present in the body of the worms was usually 

 obtained by cutting off the posterior end of medium-sized to large-sized 

 specimens and allowing the pinkish liquid to drop into a test tube. 

 Fluid obtained in this manner does not keep well and is available only 

 for immediate use. Allowed to stand, even at a low temperature, the 

 body fluid thus collected undergoes bacterial decomposition in about 24 

 to 36 hours. Weinberg and Julien (1911) describe a method of col- 

 lecting Ascaris body fluid under aseptic precautions. Briefly, the 

 method consists in drying the worms with filter paper, holding the ends 

 of each specimen and passing the middle region of the worm through the 

 flame of a Bunsen burner until the cuticle bursts. The first two or three 

 drops of fluid which ooze out are discarded and the remaining fluid is 

 allowed to drop into a sterile tube. This procedure was tested by the 

 present writer with inconstant results so far as the keeping qualities of 



