64 HISTORY AND CAUSE OF THE COCONUT BUD-EOT. 



extensive studies of the identity of the organism inoculated, isolated, 

 reinoculated, and reisolated, and for convenience are designated 

 in the culture work as coconut Nos. 1, 2, 3, 4, 5, and 6. By the work 

 described in the following paragraphs the identitj^ of the organisms 

 in these six cultures has been determined and consequently the 

 particular organism which causes the disease is ascertained. In the 

 course of the work such a close similarity of the coconut organism 

 with Bacillus coli was observed that comparison of the two organisms 

 was made in most of the cultures. 



CULTURAL EXPERIMENTS. 



Studies of the Group Characteristics op the Organism, 

 morphology of organism and colony. 



The organism causing the coconut bud-rot is a short rod with 

 rounded ends, averaging 1.5 to 1.8 /t in length, and 0.5 /x in \\ddth, 

 although in length they may vary from 0.63 to 4.03 /x, and in wadth 

 from 0.48 to 0.6 /x. They occur singly, or more commonly in groups 

 of two or three; not infrequently they may be found in chains up to 

 20 fi in length. The rods are actively motile with several peritri- 

 chiate flagella (demonstrated ^\dth Lomt's flagella stain) three to four 

 times the length of the organism. Single rods dart about often with 

 a rapid, vibratoiy motion and sometimes a whirling motion. They 

 also glide from place to place without any apparent vibration. 

 Couples, when in progression, usually move Anth a bending, waving 

 sort of motion. Occasionally, when in twos or threes, the rods appear 

 almost rigid, but seem to vibrate rapidly at both ends as they ghde 

 along. The rods are nonsporulating. Thin-walled capsules are 

 readily apparent when the organism is stained with Lowit's flagella 

 stain. With this stain, also, dense bodies appear within the rods, 

 located either centrally or more or less laterally. The organism 

 does not stain by Gram's method. 



On agar plates the organism is variable. The typical surface 

 colonies are slightly raised, white, and semiopaque. Frequently 

 they eventually become lobed or radiate branched, or from the 

 beginning they may be thin and deepty lobed or radiate branched, 

 with a dense nucleus in the center. They are always wet shining; 

 white by direct light and bluish in transmitted Hght. The surface is 

 always smooth. By transmitted light the thin colony appears 

 homogeneous, but the raised colony or raised margin of the tliin 

 colony appears to have streaks more in some parts than in others. 

 In 24 hours the thin colonies may extend 5 or more centimeters on 

 the petri dish, and in 48 hours they frequently cover the dish. The 

 moisture conditions affect the form and density of the colony. 



228 



