156 



It would therefore appear, that this form of spiral vessel is by no 

 means rare, but still the recorded instances of its occurrence are not 

 so numerous as to render a further enumeration of plants in which it 

 may be found, destitute of interest. 



EXPLANATION OF PART OF PLATE XIX. 



Fig. 1. A magnified portion of the spiral vessel of the Vegetable Marrow. 

 Fig. 2 and 3. The same unrolled. 



