148 KANSAS UNIVERSITY SCIENCE BULLETIN. 



notice. So numerous are these species that it has not been 

 necessary for me to search for material in other parts of the 

 state. The species included in this report, therefore, are those 

 found in Lawrence, Kan., or its immediate environs. 



In working with Infusoria one soon learns that his classifica- 

 tion and most of his drawing must be done from the living 

 animal, for, when killed, nearly all species of Infusoria become 

 abnormally distorted and lose all evidence of ciliation. Even 

 the best-preserved species are unreliable. My method with 

 those forms which do not become distorted when killed has 

 been to make a free-hand drawing of the animal when alive, 

 showing all of the details then visible, and a second camera- 

 lucida drawing of the animal after it has been fixed and stained, 

 showing the outline of the body, of the nuclei, and of any other 

 structures that have been sufficiently well preserved. The two 

 drawings were then used to supplement each other in the fin- 

 ished plate. In a great many cases I have been able to keep the 

 specimen under observation quiet for a sufficient length of time 

 to enable me to get a hasty camera-lucida sketch of the living 

 animal. This method was necessary in dealing with those 

 animals which contract or become greatly distorted when killed, 

 and was used whenever possible. In a few cases, chiefly with 

 large forms like Spirostomum, I was compelled to construct 

 the drawings from measurements taken. 



The fixatives and stains used were, for the most part, those in 

 general use for Protozoa ; and the fixative or stain best adapted 

 to a particular form had to be decided upon by experimenting. 

 I have found an aqueous solution of corrosive sublimate plus 

 5 per cent acetic acid very useful in killing some easily distorted 

 forms. Schneider's aceto-carmine has proved to be a very con- 

 venient, quick, combined fixative and stain where delicate cyto- 

 logical mounts are not required. This fluid kills many Infusoria 

 in better condition than any other I have used. 



One of the chief difficulties in dealing with Infusoria is to 

 get them sufficiently quiet to make out the structural details. 

 In this a weak solution of tannin in distilled water served me 

 best. It worked especially well with Hypotrichs where the 

 ciliation is not only difficult to make out but very important in 



