INOCULATION EXPERIMENTS. 89 



PITCAIRNIA TO BEAN. 



Six young pods on a plant in the greenhouse were inoculated by 

 immersion in sterile water containing conidia. No signs of infection 

 ever appeared. 



PITCAIRNIA TO COTTON. 



The stigmas of two flowers of a greenhouse plant were inoculated 

 with conidia in sterile water. The young bolls soon dropped off. 

 These were placed in a moist chamber, but no Gloeosporium ever 

 developed. 



POMELO TO APPLE. 



Three apples were inoculated by puncture with conidia from a 

 culture. Infection followed in all cases. Spots 2 centimeters in 

 diameter developed at the end of a week and acervuli formed. 



POMELO TO GRAPE. 



Eight mature berries of a Niagara grape were inoculated by 

 puncture with conidia from a culture. At the end of two weeks 

 the berries were mostly rotten, and acervuli were found on six 

 of them. 



POMELO TO POMELO. 



Two sound fruits were inoculated by applying conidia in sterile 

 water to the uninjured surface. The conidia germinated, and a 

 slight development of mycelium with scattered conidia and chlamy- 

 dospores appeared on the surface but the tissue beneath remained 

 sound. No rot developed. In another case the same experiment 

 was tried, applying the spores to the surface which had been injured 

 by red spiders. The results were exactly the same as in the case 

 just mentioned. No rot developed. 



PRIVET TO BEAN. 



Six young pods from a greenhouse plant were inoculated by 

 immersion in sterile water containing conidia. No signs of infection 

 ever appeared. 



RUBBER PLANT TO FIG. 



Four figs were inoculated by puncture with conidia from a leaf. 

 Rot developed in all cases. Four other fruits were inoculated by 

 application of conidia in sterile water to the uninjured surface of 

 the figs. Rot developed but did not appear to start immediately 

 at the point of application of the spores and as one of the checks 

 in this experiment also developed rot the results are uncertain. 

 Both lots of figs are shown in Plate XVII. 



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