314 



SCIENCE. 



[N. S. Vol. XVI. No. 399. 



cipitate when poured into three volumes of 

 absolute alcohol. This precipitate, when col- 

 lected, thoroughly washed until wholly free 

 from acid, dried and pulverized, induces, when 

 injected into animals, the symptoms and le- 

 sions of colon intoxication. So far this 

 method of extracting the cellular toxins has 

 been applied to the colon bacillus, and the 

 bacilli of anthrax and diphtheria. These 

 pathogenic organisms have all yielded, when 

 treated with dilute sulphuric acid, toxins 

 which, when injected into animals either sub- 

 cutaneously or intraperitoneally, induce the 

 symptoms and lesions which follow inocula- 

 tion with virulent living cultures. The space 

 limitation has already been exceeded, and we 

 will have to omit a discussion of the properties 

 of these intracellular toxins. 



A BACTERIAL SOFT EOT OF CERTAIN CRUCIFEROUS 

 PLANTS AND AMORPHOPHALLUS SIMLENSE.* 



For several years the writers have had un- 

 der observation a soft rot of certain crucifer- 

 ous plants, particularly cabbage and cauli- 

 flower. During epidemics of black rot, Pseu- 

 domonas campestris (Pam.) Smith, in both 

 cabbage and cauliflower it often happens that 

 much damage is done by a soft rot. At first 

 this soft rot was supposed to be merely a viru- 

 lent form of black rot; but it was found that 

 severe attacks of soft rot may occur in fields 

 where there is little or no black rot. Especial- 

 ly is this true of seed cabbage. On Long 

 Island the production of cabbage seed is an 

 important industry, and one of the chief ene- 

 mies to the crop is a soft rot which attacks 

 the plants during winter storage in trenches 

 and also at the time of blooming. In storage 

 the plants are attacked just below the head. 

 In the field this portion of the stem rots, caus- 

 ing the plant to suddenly wilt and die while 

 in bloom. 



In the cauliflower fields on Long Island one 

 may find at any time during August, Septem- 

 ber and October plants which have suddenly 

 collapsed with soft rot of the stem. From a 

 plant thus affected the writers, in September, 



* A preliminary report read before Section G 

 of the A. A. A. "S. at Pittsburgh, Pa., June 30, 

 1902. 



1901, isolated an organism which in their notes 

 was designated 0.2 E. Pure cultures of this 

 organism were inoculated into cabbage and 

 cauliflower plants in pots in the greenhouse 

 in the following manner : A leaf springing 

 from the fleshy portion of the stem was cut 

 off close to the stem with a sterilized scalpel. 

 Through the sterile surface thus formed the 

 stem was punctured to the center by means 

 of a needle which had been first sterilized and 

 then dipped into a fresh culture of the organ- 

 ism. Finally the wound was smeared over 

 with melted grafting wax. In this manner 

 numerous plants of cabbage and cauliflower 

 were inoculated at various times between 

 March 10 and June 17. With one exception 

 all of these plants became much rotten at the 

 point of inoculation, whereas in the same 

 number of check plants none showed any rot 

 or discoloration whatever. The extent of the 

 rotting seemed to depend largely upon the 

 condition of the plant. On thrifty young 

 plants it progressed with wonderful rapidity. 

 Thrifty cabbage plants, two months old, nine 

 inches high and with stems of the size of a 

 lead pencil were so much rotted at the end of 

 forty hours after inoculation that their own 

 weight caused them to break over at the point 

 of inoculation. On old, woody, slow-growing 

 plants unmistakable signs of rot appear in 

 from two to four days after inoculation; but 

 in the majority of cases such plants are only 

 checked in growth and not killed outright. 



In most cases the rot first appears as a 

 slight discoloration around the point of inocu- 

 lation, works very rapidly for a few days, then 

 stops. At first the rotten tissue is soft and 

 mushy and watersoaked in appearance, but it 

 soon dries and mostly disappears, leaving only 

 a cavity lined with shreds of dry, blackened 

 tissue. 



Cabbage and cauliflower leaves inoculated 

 in the petioles usually become broken over and 

 soft rotten at the point of inoculation within 

 forty-eight hours. Inoculations made in the 

 blade of the leaf produce no marked results 

 unless a large vein is punctured, in which 

 ease soft rot follows as with petiole inocula- 

 tions. However, on the leaves of plants under 

 bell-jars circular, dead, brown spots sometimes 



