OF LOWER GREEKS AND PLANTS. 



171 



the same tangent alternate so as to fit into each other. Resin- 

 canals are entirely absent in the type-specimen ; but resin- 

 containing zylem- parenchyma is remarkably abundant and 

 conspicuous (see PI. XV, fig. 2). In a specimen I found at 

 Luccomb (V. 13193) a large number of traumatic resin-canals 

 lie in a close series extending about halfway round the annual 

 ring. In another section of the same specimen, in addition to 

 this half-circle of canals, there are several series of resin-canals 

 in the wood-rings just in front of an outgoing branch. 



Text-fig. 18. Transverse section of branch of Cupressinoxylon 

 Barber, showing the composite growth-rings, ca. X 3'5. After Barber. 



Medullary rays are numerous, fairly conspicuous, and from 

 1 to 10 tracheids distant, principally 4-6. The rays are uni- 

 seriate, 1 to 10 cells high, by far the greatest number being 

 from 2 to 4 cells high. 



DETAILS OF ELEMENTS. The large rounded elements of the 

 pith vary from 10 to 50 yu in diameter according to Barber : my 



