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Professor W. C. Williamson, F.RS., gave a practical 
demonstration by means of sections, shown by the oxy- 
hydrogen camera, of the structure and development of 
young roots. Beginning with those of the Maize, as they 
appear within the seed ; those of the Vine, of the Bean, of 
the Crown Imperial, and of several species of Cycads were 
exhibited and explained, illustrating the changes which 
roots undergo between the uniform structure seen near the 
root or tip, to their more advanced .condition, as seen, first 
in the roots of Endogenous plants, and afterwards in the 
more complicated ones of Exogens. 
