n9 



OX BACTERIAL DISEASES OF THE ROOTS OF THE LEGUMINOSiE. 



any other plant. A number of experiments were made to ascer- 

 tain if plants could be grown free from these diseases, and with 

 care it was found possible to do so. 



I also artificially cultivated, on a broth made of beans and 

 thickened to a jelly with agar-agar, some of these bacteria. I 

 afterwards found that " Tubercular root-diseases of the Legu- 

 minosse " was a subject upon which much attention had been 

 bestowed in Europe, especially in Germany. Professor Marshall 

 Ward of London has studied these diseases carefully for many 

 years past, and has contributed much to the Transactions of the 

 Koyal Society upon the subject ; he found that the more a plant 

 was affected with the disease the better it grew ; the bacteria help 

 the plant to assimilate nitrogen and are a benefit to it. 



Although this subject has been so ably worked up in Europe, I 

 hope these notes will not be unacceptable to the Society, as no 

 record, as far as I am aware, of root-diseases of bacterial origin 

 has been made in Australia. 



Brisbane, March, 1893. 



EXPLANATION OB' PLATE. 



The roots of five leguminous plants affected with bacteria. Commencing 

 in order from the top, the plants are Mimosa, Sesbania, Desmodiian, 

 Medicago, and Crotalaria. 



(Reproduced from a life-size photograph.) 



