78 THE SALTON SEA. 



ized strips of filter paper were then placed in this solution, and flasks containing these prepa- 

 rations were inoculated with 10 to 50 c.c. of water from the different cultures of the Salton 

 Sea woods. These were incubated at room temperature and, of course, accompanied by 

 controls. At the expiration of a week's time, a slight cloudiness was observed in the inocu- 

 lated cultures. Within a few days small colonies were observed growing on the filter paper. 

 These conformed in essential respects to the group of organisms described by Omelianski 

 as capable of carrying on hydrolysis of cellulose. They were isolated most satisfactorily 

 from the culture of Salton Sea water containing Prosopis glandulosa. There was every evi- 

 dence that successful cultures depended upon using large quantities of the inoculating fluid, 

 though it is probable that small pieces of the infected wood might have been far more 

 effective as an inoculating agent than was the water in which the wood was immersed. 



In view of the findings of the authorities quoted there seems to be no question 

 that the disintegration of cambial cell walls and consequent removal of the cortical and 

 phloem portions of woody plants submerged in brackish waters is to be attributed to the 

 action of bacterial organisms belonging to the Amylobacter group. From this it would 

 seem that the present problem and the mass erosion carried on by substances present in 

 the water where flax and hemp are retted are related to such economic problems as the 

 breaking down of cellulose or its related compounds when they pass through the digestive 

 tract of animals, or through the septic tank of sewage-disposal plants, and also to the 

 ultimate breaking down of the mantle of humus overspreading the earth. 1 



SUMMARY. 



1. Woody plants submerged by the flooding of the Salton Sea were found to be decor- 

 ticated after a period of one year. 



2. Microscopical preparations of samples of fresh woods placed in Salton water and 

 kept under control were found breaking down in the zone of meristematic cells, notably 

 in the region of the cambium and in the zones between lignified regions of the phloem. 



3. The chemical composition of Salton water could not account for the decortication 

 of woody plants submerged in the sea for a period of one to five years. 



4. Sterilized specimens of fresh woods placed in sterilized Salton water did not 

 decorticate during the ten months they were kept under inspection. 



5. Bacteriological cultures made it possible to isolate the bacterial organisms, belong- 

 ing to the Amylobacter group, which produce an enzyme capable of hydrolyzing pectins 

 which are considered by some chemists to be the principal substances in young cell walls. 



6. A microscopical study of woods which emerged annually from the autumn of 

 1907 to 1911 did not show breaking down of cell walls in any portion of the wood cylinder. 

 Cell walls of the same tissue in the woody specimens of all the species examined were 

 characterized by the same general thickness. 



Consequently, it is believed that the action of the Salton Sea water on tissues of 

 woody plants is wholly related to hydrolyzing agents having a bacterial origin; and, 

 furthermore, evidence is lacking that petrifaction had begun in the tissues of the woody 

 plants submerged for four years in the Salton Sea. 



It is a pleasure to make grateful acknowledgment of the helpful suggestions received 

 from Prof. John M. Coulter and Dr. W. J. G. Land during the time that these investi- 

 gations were continued. I am especially indebted to Dr. Land for valuable directions in 

 developing technique suitable for making microscopical preparations of the bone-hard 

 specimens of dead woods which were received from the Salton Sea for study. 



