444 



When the intumescence is highly developed, the over-elongation extends 

 backward to the secondary bark, stretching the cells of the phloem rays (q). 

 In fact, cases occur in which the woodring seems stimulated in those layers 

 last formed because the outermost cambial layers are constructed of paren- 

 chyma wood. As on the various kinds of Eucalyptus, the intumescences 

 occur most frequently on the side of the branch turned toward the light, 

 and often only then. After the explanation given these cases, a more 

 thorough discussion is needed here. 



Fig. S3. Blossom.s of Cymbidium Lowi with sland-like intumescence (a) on the 

 tops of tlic iiei-iuntli. (Ori^.) 



Intumescences occur most rarely on blossom organs. I observed one 

 such case in Cymbidium Loivi. The blossoms, normally large and otherwise 

 well-developed, exhibited on the under side of the perianth, quince yellow or 

 yellowish green, hemispherical bosses (Fig. 83a) ; exactly the same struc- 

 tures could be found also on the ovaries. In an immature stage they had 

 a smooth upper surface, later they cracked open in the apical region and 

 became depressed like a funnel. In the older knots, the depression advanced 

 to complete perforation of the perianth tip. For this reason the blossoms 

 were unsalable. In Fig. 84, it may be seen that the cell layer found beneath 



