[Vol. 2 



660 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



The seed employed were sterilized by means of a method 

 devised in the Laboratory of Plant Physiology of Cornell 

 University by Dr. J. K. AVilson. 1 In brief it is as follows : 10 

 grams of chloride of lime are shaken up with 150 cc. tap water 

 and after standing for ten minutes the supernatant liquid is 

 filtered. The filtrate is used as the sterilizine: agent. The 



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seeds are placed in a test-tube covered with about five times 

 their volume of the filtrate and the tube then tightly stoppered. 

 The seeds are treated for from 4 to 24 hours, depending upon 

 the character of the seed. In the experiments here mentioned 

 the vetch seeds were exposed to this treatment for 12 hours 

 and the peas for 4 hours. The seeds are directly transferred 

 to the culture vessels from the chloride of lime solution, care 

 being observed to drain off all of the chloride of lime solu- 

 tion. In transferring the seed the usual bacteriological pre- 

 cautions are observed. 



Experiment with vetch (Vicia villosa). — The plants were 

 grown in large glass cylinders 60 cm. high and 10 cm. in 

 diameter, having a volume of approximately 4 liters. In each 

 of the cylinders were placed 250 cc. of the nutrient solution 

 plus 1 per cent washed agar and galactose sugar. The 

 cylinders were then fitted with cotton plugs and sterilized for 

 one hour in an autoclave at a pressure of 15 pounds. The 

 cultures were made in triplicate and the galactose was tested 

 at 2 per cent and at 0.2 per cent concentration. After a 

 grow r th period of 30 days the cultures showed the injurious 

 action of the galactose, in each case the roots being markedly 

 injured. The primary root tip coming in contact with the 

 agar medium was killed and the lateral root produced met 



w r ith the same injury, so that ultimately a multi-branched 

 root system was produced after the manner of the pea roots 

 shown in pi. 22 fig. 5. Whatever portions of the roots re- 

 mained in contact with the agar medium were ultimately 

 killed. It should be mentioned in this connection that the 

 vetch grown in the presence of glucose, saccharose, lactose or 

 maltose at concentrations of 2 per cent was greatly benefited. 

 These sugars are absorbed and assimilated. 



1 Am. Jour. Bot. 2: 420-427. 1015. 



