440 



SCIENCE. 



[N. S. Vol. XXII. No. 562. 



in another problem, have proved intrinsically 

 interesting. 



In the fall of 1903 I determined the organ- 

 isms present on the grain in twelve rice fields. 

 In 1904 I studied both the flowers and grain 

 in eight of the twelve fields examined the year 

 before, and in four other fields. In 1904 I 

 also studied, for comparison, the flowers and 

 grain in eight wheat fields, and six oat fields; 

 also the flowers and fruit in three peach 

 orchards, flowers and fruit in two asparagus 

 patches, and flowers and fruit in one patch of 

 the wild Iris verna L. A few comparative 

 studies of organisms on the fruit or flowers 

 and the leaves of the same plant were also 

 made. In every case exactly fifty grains or 

 flowers or fruits, as the case might be, were 

 taken at random from each field or patch, in 

 the case of the cereals only one grain from 

 any one spike. Each one was shaken in 

 sterile water, allowed to stand for about an 

 hour, shaken again, and the whole added to 

 sterile agar-agar and plated; except in the 

 case of peaches, when only a portion of the 

 water was plated. The resulting organisms 

 were studied in greater or less detail, accord- 

 ing to their interest. 



A part of the conclusions to date are as 

 follows : 



1. An immense but variable number and 

 variety of micro-organisms were normally 



the same locality, and showed no constant 

 association with the host plants studied. 



2. Without exception, the same organisms 

 that occurred on the flower could later be 

 found on the fruit, but not in the same quan- 

 tity. But organisms commonly occurred on 

 the fruit that were not found on the flower. 



3. The most constantly present organisms 

 were certain yeasts; in greatest number and 

 variety on the peach, asparagus and iris; but 

 yet characteristically present on the cereals. 



4. The bacteria on the flowers and fruit 

 were not different in kind from those on the 

 leaves of ' the same plant, nor, so far as 

 studied, materially different in number, area 

 for area. With the peach, asparagus and 

 iris fungi, and especially yeasts, occurred in 

 noticeably greater number on the flower and 

 fruit than on the leaf. 



5. Bacteria giving the standard reactions 

 of the colon group were found in thirteen out 

 of the sixteen rice flelds examined, five of the 

 eight wheat fields and all of the oat fields. 

 All three peach orchards and both asparagus 

 patches exhibited coli forms in both flower 

 and fruit; but none were found on either 

 flower or fruit of Iris verna. In the follow- 

 ing tables are shown the proportion of flowers 

 and fruits (each flower or grain in the cereals 

 representing a spike) found to have coli forms 

 on the surface: 



present on the surface of flowers, fruits and 

 leaves. These were different in different lo- 

 calities, and different in successive years in 



An asterisk indicates that there were in the 

 field in question very obvious means of con- 

 tamination by human or animal excrement at 



