SCHONFELD, NOVEMBER 15, 1873. - 17 



sftlly accepted. Schonfold/ therefore, set about to supply incoutro- 

 vertiblo evidence to j)rovo the cause of infectious foul brood. He 

 received a small mass of decaying larvte about tJie size of a pea and 

 placed it under an inverted funnellike apparatus. An opening for 

 the admission of air was made from below; the exit was an opening 

 above in which was placed a stopper made of cotton. Plachig tliis 

 apparatus near the window, that it might receive the heat of the sun, 

 he hoped, by the current of air which would thus be produced, to 

 collect on the cotton, filling the exit, the spores of the fungus which 

 would be floating off in the air from the foul-brood mass. Upon 

 examining the cotton he found what he supposed was the fungus in 

 the fomi of a micrococcus. This was the first part of his experiment. 

 In the second part of it he used this cotton to infect healthy larvae. 

 Four square mches of brood was covered by a layer of cotton. The 

 cotton was taken from one of the stoppers that had been contami- 

 nated with the fungus by means of the apparatus. After two unsuc- 

 cessful trials he made a third attempt, which was considered by him 

 as being successful. After a lapse of four days seven larvse had 

 died and numerous micrococci were found in their dead bodies. 



In another experiment the same author used the larv£e of the blow- 

 fly (Musca), Calliphora vomitoria. Some cotton contaminated in 

 the manner outlined in his first experiment was placed upon some 

 meat upon which these larvae were feeding. Nine days after adding 

 his supposed virus he found dead larvae which upon microscopic 

 examination revealed to him again the presence of numerous micro- 

 cocci. The results of these experiments convinced him that tliis 

 liiicrococcus was the cause of infectious foul brood, and he believed 

 that the fact would be accepted without question. 



The experiments of Schonfeld were not, however, universally 

 accepted as conclusive. This induced him to perform other infec- 

 tion experunents. This time he used caterpillars of (Pieris) Pontia 

 hrassicse and (Pieris) Pontia rapse. The virus was mixed in dis- 

 tilled water and painted on the exterior of the insect, with the result 

 that those so treated died while the checks developed normally to 

 healthy pupae. Microscopically, however, the check caterpillars 

 showed also the presence of the fungus. This caused him to doubt 

 somewhat his conclusions relative to the blowfly experiment. He 

 believed, however, that sufficient evidence had now been produced 

 to justify the conclusion that infectious foul brood is a mycosis and 

 that the fungus Cryptococcus alvearis is the exciting cause of the 

 disease. 



1 Schonfeld, Dr., November 15, 1873. Faulbrut-studien, Pt. I. Elchstadt Bienenzeitung, 29 Jahrg., Nro. 

 21, pp. 250-254; January 15, 1874. Faulbrut-studien, Pt. II, Eichstadt Bienenzeitung, 30 Jahrg., Nro. 1, 

 pp. 3-5. 



13140°— Bull. 98—12 2 



