54 Proceedings of Ninth Annual Meeting 



tions of carbon dioxide and ammonia. The first substances to be 

 tested were, therefore, these two end products of the decomposi- 

 tion of all the secretory and excretory products. The investi- 

 gation during the past summer has been limited to experiments 

 on sollicitans and cantator. It was found that carbon dioxide 

 and ammonia with a particular temperature and degree of 

 moisture such as to reproduce the conditions of the breath was 

 highly attractive. 



The gross secretions and excretions such as sweat, urine, 

 sebaceous secretions, feces and breath were experimented with 

 and it was found that none except breath were attractive. 



The idea that possibly the intermediate decomposition products 

 ^ of these secretions and excretions other than the breath might be 

 attractive even though the gross secretions themselves were not, 

 occurred to the investigator and an examination of the literature 

 bearing upon the decomposition of these gross secretions was 

 undertaken. The principle intermediate decomposition products 

 of these secretions and excretions insofar as they could be se- 

 cured were then tried out. Of the decomposition products O'f 

 urine and perspiration, phenylalamine, alanine and asparactic 

 acid were more or less attractive. Of the intermediate decom- 

 position products of the sebaceaus secretions, chelesterol, benzoic 

 acid and a combination of oleic acid and benzoic acid were more 

 or less attractive. Of the intermediate decomposition products 

 of feces none were attractive. Blood itself was not attractive, 

 although warm beef bouillon was. Hemoglobin was attractive. 

 Since the intermediate decomposition products of peptone would 

 include the ones found primarily attractive in preceding studies, 

 peptone itself was given a thorough trial and was found to be at 

 body heat exceedingly attractive. 



Evidently the only gross excretion of the human body that is 

 attractive to mosquito-es is the breath in which we find both 

 carbon dioxide and ammonia as well as a high percentage of 

 atmospheric moisture. Certain of the intermediate decomposi- 

 tion products of the other gross excretions and secretions are 

 also attractive and the ultimate or final decomposition products 

 of all the gross secretions and excretions are attractive. 



Thus it appears that we have found what it is in the emana- 

 tions of man that are attractive to the mosquito, but the problem 

 is to produce them in such quantities as to similate their produc- 

 tion from a large animal like man. With the opening of the 

 mosquito season it is planned to continue these studies and to 

 attempt to solve this problem. It is planned to extend the results 

 obtained from a study of sollicitans arid cantator to the other 



