198 R. T. BAKER AND H. G. SMITH. 



epidermal cells adjacent to the palisade parenchyma form 

 a conspicuous object below the cuticle: and under a 325 

 magnification, the dark long lines in the vascular bundle 

 can easily be determined as spiral and annular vessels, the 

 latter being nearer the centre; other vessels which are 

 well brought out, are referred to when dealing fully with 

 the transverse sections. Air cavities have missed the edge 

 of the knife in this instance, but are shown to be fairly 

 numerous on the right hand edge of figure 1. 



Transverse Sections. — In the transverse sections some 

 interesting details are to be recorded. The terete character 

 of the leaf gives to them an almost circular shape in section. 

 In Fig. 3, the photograph depicts a portion of the leaf contain- 

 ing no oil glands. The two rows of palisade parenchymatous 

 cells are well defined, as well as the fibro-vascular stele 

 subtended by two smaller collateral bundles in the middle 

 plane of the picture, and the numerous dark endodermic 

 cells surrounding the bundles, the whole not being much 

 unlike a section of a deep sea cable in appearance. In this 

 as in all other sections the phloem is convex to the lower 

 surface of the leaf. 



Fig. 4 has twice the magnification (160) of Fig. 3; this is 

 taken from the upper left hand portion of that section, and 

 is reproduced to show the two stomata with guard cells at 

 the top of the epidermic curve, these not being discernible 

 in the previous picture. 



Fig. 5 (magnified 80 times) one oil gland and part of 

 another are seen in the top left hand portion of the section. 

 These glands are of value here as they demonstrate the 

 gradual displacement of the various vessels in the evolution 

 of the gland, thus proving that in this species these bodies 

 are of lysigenous origin. This displacement is further 

 illustrated in photographs 6, 7, and 8, and what is also 

 worthy of notice is the gradual diminution of endodermic 



