182 R. T. BAKER AND H. G. SMITH. 
text is well reproduced. The division of the median structure into 
three bundles by obtruding medullary pith cells, and the orienta- 
tion of the phloem (indicated by the darker cells) are well brought 
out, x80. 
Fig. 4.—This section is interesting in that one or two elongated 
cuticle processes are seen on the lower of the assimilating surface. 
No oil glands occur in this or previous sections, where also the 
endodermic and transfusion cells are not arranged in any order. 
The ventral surfaces on the two left concrescences have edged 
together and so shut out any communication between the air and 
the stomata. x 80. 
Fig. 5.—Oil cells together with the dark secretory cells of the 
walls in the lower and right hand concrescence are seen. The 
endodermic cells are here assuming some kind of order, and in 
Fig. 6 are clustered around the resin cells and at the base of the 
ventral surfaces. The bundle of each leaf is clearly seen below 
each oil gland. x 80. 
Fig. 7—The ventral surfaces are here shown well exposed to 
the atmosphere, and three well formed resin cells form distinct 
objects in each concrescence. The various vessels of the leaf 
structure are clearly brought out. x 80. 
Fig. 8.—An unusual form of concrescent leaf. x 80. 
Fig. 9.—This is to show the unusual occurrence of two resin 
cells in a concrescence. x 80. 
Fig. 10—Shows ventral surfaces of two concrescences exposed 
to the atmosphere, x 160. 
Fig. 11.—The method of protecting the ventral surfaces from 
the atmosphere by the closing over of the edges of the dorsal 
surfaces is seen at top of the picture. The origin of the cuticle 
elongations are clearly seen in this picture. x 160. 
Fig. 12.—The leaf structure is well defined, especially at the 
locality of the oil cell. x 160. 
Fig. 13. —A much finer illustration of the remarks under Fig. 11. 
The cuticle prolongations are well marked. x 160. 
