122 KANSAS Academy of science. 



The laboratory experiments have been continued through the season. Of the 

 three diseases identified, that produced by the Trichoderma appears to be less fatal 

 than the other two, as is indicated by the following laboratory notes: 



"September 28th, dead chinch-bugs, showing no signs of fungus externally, were 

 taken from the infection jars and crushed on a glass slide in distilled water. Oval 

 hyphal bodies of a fungus {Trichoderma) were found in considerable number. These 

 were put under a bell jar. 



"September 29th, some of the hyphal bodies had put out slender, mycelial 

 growths; others in immense numbers were multiplying by division. 



"October 1st, the hyphal bodies were still multiplying by division. The mycelial 

 growths had become much larger, and in some instances had variously branched. 



" October 3d, a dead chinch-bug taken from an infected field was crushed on a glass 

 slide in distilled water. Both round and oval hyphal bodies were found in consid- 

 erable number. These were put under a bell jar to prevent drying. 



"October 4th, both round and oval hyphal bodies were multiplying by division, 

 and were putting out mycelial growths. 



"October 5th, fresh chinch-bugs, from an uninfected field, were immersed in the 

 liquid containing the above fungi, and were put in a new jar with young corn 

 plants." 



The following is a summary of the results of the field experiments in the sea- 

 son of 1890 : 



Number of boxes of diseased bugs sent out, thirty-eight. Seven of these lots 

 were either not received, or received and not used. Reports were received from 

 twenty-six of the thirty-one remaining cases. Of these twenty-six reports, three were 

 unfavorable, nineteen favorable, and four doubtful concerning the success of the 

 experiment. These doubtful cases are not to be looked upon as unfavorable, but 

 more evidence is needed to transfer them to the list of favorable reports. These 

 nineteen out of twenty-six reports, or seventy-three per cent., were decidedly favor- 

 able. The experiments will be continued during the season of 1891. 



In presenting this paper I wish to acknowledge the invaluable aid continually 

 received during the progress of the work from my assistants, Messrs. W. C. Stevens 

 and V. L. Kellogg. 



SOME EXPERIMENTAL TESTS OF THE PASTEUR FILTER. 



L. E. SAYBE AND V. L. KELLOGG, LAWEENOE. 



It is claimed for the Pasteur filter that it perfectly filters water ( or other liquids) 

 of, among other impurities, bacteria ; that water teeming with disease-producing 

 germs after being filtered by means of this contrivance, is wholly free from their 

 presence. The filter is well known ; to the few who may not have seen it, it may be 

 said that an unglazed earthenware cylinder closed at one end is introduced into a 

 metal cistern or jacket, which may be filled with water, or other fluid. The open 

 end of the filter projects from the cistern through a perfectly tight collar. The fluid 

 in the cistern filters through the cylindrical earthenware cup, and is received from 

 its projecting open end. 



It is evident at first glance after filtering nutrient solutions, as hay and turnip 

 infusions turbid with bacilli, that the filter restrains the great majority of the 

 minute forms from passing into the earthenware cup with the liquid, as the filtered 

 fluid is always clear and colorless. No interception and reflection of light from the 

 microscopic bits of life is to be noted by the naked eye on examining the filtered 



