NOTES ON MELILOTUS ALBA 
417 
approximately the same level. The anthers are versatile and 
introrse. The pistil is elongate, oval in cross section and is pro- 
longed above into a filiform style which curves over slightly 
toward the standard and terminates in a globose papillate stigma. 
An extremely narrow stylar canal is present. 
Fig. .82. — 3, Portion from cross section of mature stem; showing frequency 
of tracheae in the wood and amount of hasti in the cortex. b, hast ; tr, 
tracheae. 4, Portion of cortex in cross section showing bast. 
MICROSPORANGIUM AND POLLEN DEVELOPMENT. 
The anther first appears as an oval mass of meristematic cells 
which very soon become four lobed in cross section. It flattens 
along the sides through pressure of the surrounding parts and the 
outer side becomes slightly wider than the inner. The radially 
elongated cells of the hypodermal layer divide by periclinal 
walls and the outer cells develop into the parietal layers while 
the inner develop the sporogenous tissue. 
27 
