212 PHARMACEUTICAL BOTANY 
In a tangential longitudinal section which has been cut through 
the phloem, the exact range in width of the medullary-rays may 
on 
LSS» 
<n 
‘Medullary ray 
Fic. 142.—Diagrammatic representation of a block of pine wood, highly mag- 
nified. a, Early growth; 4, late growth; c, intercellular space; d, bordered pit in 
tangential wall of late growth; m, f and e, borderéd pit in radial wall of early 
growth from different points of view; h, row of medullary cells for carrying food; 
g, row of medullary ray cells for carrying water; /, thin place in radial wall of ray 
cells that carry food. (From Stevens.) 
be ascertained. In this bark the medullary-rays are spindle- 
shaped in tangential view and one to four cells in width. 
Woop.—From a practical pharmacognic standpoint as well 
as that of the lumber trade, wood is all that portion of woody 
exogenous plant axis inside of the cambium line. In Dicotyl 
