SUMMARY. 33 



SUMMARY. 



After testing the various methods as above indicated, the writer 

 finds that the best results in routine examinations of feres of all 

 kinds are obtained from the simple method already given. Briefly, 

 the method consists in breaking up the feres very thoroughly by shak- 

 ing in water, adding a quantity of small shot if necessary or desir- 

 able; sieving through a set of brass sieves and then through a silk 

 bolting-cloth sieve or a sieve made with a jeweler's fine-meshed brass 

 screen, examining the material left on the sieve for parasites: sedi- 

 ment ing (and washing) : centrifuging (and washing) one tube 

 being filled with calcium chlorid solution of l.'2.">0 specific grav- 

 ity, centrifuged, and if desired the top cubic centimeter removed with 

 a pipette, shaken up in a tube with 14 cubic centimeters of water and 

 centrifuged and then making a microscopic examination of a drop 

 of sediment from the bottom of the tube centrifuged with water, and 

 one from the top when the calcium chlorid solution alone was used or 

 from the bottom in case water was added to the top cubic centimeter. 

 The material is washed at either or both of the points indicated. 



ADAPTABILITY ()!' METHOD. 



The writer does not claim that the method advocated here is the 

 best possible method. It is. however, the method which his experi- 

 ence shows to be the best for routine examination of various kinds of 

 feces after comparative tests with other methods. It serves very well 

 for the feces of man. and of the carnivora. herbivora, and birds, so 

 far as fecal examinations for representatives of the last three groups 

 indicate. It is not only of service in examining feces for worm para- 

 sites, but also for coccidia. It has not been tested for other protozoa. 

 Presumably the writer's comminution method would damage flagel- 

 lates, ciliates. or amelne. It is often useful in detecting parasitic in- 

 fection of stomach and intestinal contents. It has the advantage of 

 speed and certainty over the smear method or sedimentation methods. 

 It takes longer to make the microscopic preparation than in the smear 

 method, but the resulting concentration justifies it. Nor is it a long or 

 difficult process. The time required for each step is slight a minute 

 to shake up the feces. another to sieve them, and another to centrifuge 

 them, leaving out the sedimentation after sieving, which needs no at- 

 tention, and the time spent in examining material on the screens. 

 which examination is incidental to the technique, not part of it. As 

 everyone who has used laboratory methods knows, the total time 

 necessary to perform three one-minute operations is not just three 

 minutes or. as a rule, even six minutes, as preparation, intermediate 

 steps, cleaning up. etc.. add considerably to the time necessary. At 

 the same time, the method outlined here is reasonably rapid and 

 takes less time than is required to examine the additional slides 



