August 22, 1902.] 



SCIENCE. 



315 



appear in the parenchyma around the points 

 of inoculation. Inoculations on the heads of 

 cauliflower plants under bell-jars bring about 

 an active soft rot which in a few days involves 

 the whole head. 



Young plants of kohlrabi and Brussels 

 sprouts were caused to rot by inoculation in 

 the stem, rutabagas by inoculation in the leaf 

 petioles and radish and flat turnip by inocu- 

 lation in the fleshy root. 



Ten seed cabbages in full bloom and grow- 

 ing in the open air were inoculated with a 

 pure culture by making a puncture in the en- 

 larged portion of the stem where the head was 

 originally attached. The wounds were cov- 

 ered with grafting wax. There were ten check 

 plants. On the eighth day after inoculation 

 three plants died from soft rot at the point 

 of inoculation. None of the check plants 

 were affected. Since May 28, when these 

 plants were inoculated, there has been but a 

 single shower upon them. This, coupled with 

 the prevailing low temperature, may explain 

 why more have not yet died. 



The organism was also tested on slices of 

 uncooked carrot, turnip, potato, onion and 

 parsnip. Within twenty-four hours there 

 were large areas of soft rot around the points 

 of inoculation on all of these vegetables. Up 

 to this time the organism was supposed to be 

 different from Bacillus carotovorus Jones be- 

 cause it rots cabbage and cauliflower with 

 avidity, whereas Jones states* specifically that 

 B. carotovorus is without effect when inocu- 

 lated on cauliflower; but the behavior of 0.2 

 E on uncooked vegetables aroused the suspi- 

 cion that it might, nevertheless, be related to 

 B. carotovorus. Accordingly, an authentic 

 culture of B. carotovorus was obtained from 

 Professor Jones and inoculated into cauli- 

 flower and cabbage plants. There followed a 

 virulent soft rot strikingly like that caused 

 by 0.2 E. The two organisms were then 

 grown in parallel cultures on various culture 

 media and found to behave in about the same 

 way. .Thus it appears highly probable that 



* Jones, L. R., 'A Soft Rot of Carrot and Other 

 Vegetables.' Ann.. Rep. Vermont Exp. Sta., 13: 

 310, 1900; also, Centralbl. f. Bakt. Pwrasitenh. u. 

 InfekUonslcr., II. Abt., 7: 15. 



the germ 0.2 E is closely related to, if not 

 identical with, Bacillus carotovorus Jones. 



Besides 0.2 E there have been isolated sev- 

 eral other similar organisms which produce 

 soft rot when inoculated into cabbage and 

 cauliflower plants. Two such germs were 

 obtained from rutabagas affected with a de- 

 structive soft rot in a garden at Phelps, N. T., 

 in 1901; one from stored cabbages on Long 

 Island; several from seed cabbage plants dying 

 with stem rot while in bloom; and two from 

 Amorphophallus simlense, a member of the 

 Aracese cultivated by florists. Since 1897 the 

 writers have each year observed a destructive 

 soft rot which attacks the petioles of A. sim- 

 lense during June and July and causes the 

 death of many leaves. The petioles of this 

 plant are often two feet in length, an inch in 

 diameter at the base and very juicy. The 

 bacterial nature of this disease has been prov- 

 ed by inoculation experiments made in 1897, 

 1900 and 1901. Quite recently the Amor- 

 phophallus germs have been compared with 

 0.2 E and the other cabbage rot organisms and 

 found to agree very closely with them. The 

 Amorphophallus germs inoculated into cab- 

 bage plants produce soft rot and 0.2 E, and 

 the germs from rutabaga when inoculated into 

 Ajnorphophallus produce a soft rot of that 

 plant. 



Thus we have several bacterial forms which 

 produce a violent soft rot of cabbage, cauli- 

 flower and several other crucifers and at least 

 four of them also attack Amorphophallus sim- 

 lense. It is likely that the list of host plants, 

 and, perhaps, also the number of organisms, 

 will be enlarged by future studies. The rela- 

 tionship of the various forms has not been 

 fully worked out, but the present indications 

 are that we have here to do with a group of 

 organisms closely related to each other and to 

 Bacillus carotovorus Jones, but presenting cer- 

 tain minor differences which may cause them 

 to ranlv as varieties of B. carotovorus or, pos- 

 sibly, as separate species. 



When completed, a full account of this in- 

 vestigation will be published in a bulletin of 

 the New York Agricultural Experiment Sta- 

 ll. A. Harding, 

 F. C. Stewart. 



