ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 263 



BOTANY. 



GENERAL, 



Including the Anatomy and Physiology of Seed Plants. 



Structure and Development. 

 Vegetative. 



Leaf-Anatomy of Scsevola crassifolia, with Special Reference to 

 the Epidermal Secretion. — Marjorie J. Collins {Proc. Linn. Soc. 

 New South Wales, 1918, 43, 247-59, 2 pis.). This plant (a member 

 of the family Goodeuiacese) forms a pronounced element in the sand- 

 dune flora near Adelaide. It is a low-spreading shrub, the older woo:ly 

 stems of which form a dense undergrowth in which blown sand and 

 dried leaves of Fosidonia accumulate, thus helping to build up the 

 dunes. The buds and young leaves bear peltate glandular hairs which 

 secrete a sticky resin in grent quantity. As the leaves become older the 

 glands become less active, the secretion loses its moljility, dries up and 

 gives the surface of the leaf a lacquered appearance. The mature leaves 

 are thick and succulent ; the glands are sunken and no longer functional 

 on the blade of the leaf, retaining their activity only in the region of 

 the leaf-base and protecting the asilliiry buds. The mature leaves show 

 special xerophilous adaptations in the secondary increase in size of the 

 epidermal cells, the massive development of palisade tissue, the develop- 

 ment .of special water-storage cells, such as mucilage-cells, water- 

 storage tracheides, and ordinary thin-walled water-storage cells. A 

 protection from intense illumination is suggested by the yellow colour 

 of the secretion. A. B. R. 



Storied or Tier-like Structure of certain Dicotyledonous Woods. 

 — S. J. Record {Bull. Torr. Bot. Club, li)19, 46, 253). A con- 

 siderable number of dicotyledonous woods, representing a wide range 

 of families, are characterized by a storied or tier-like arrangement of 

 part or all of the elements. The writer has investigated all of the 

 woods in the extensive collection of the Yale School of Forestry, The 

 structure is shown on longitudinal sections, typically the tangential, as 

 line transverse striations, " ripple-marks," which are often visible with- 

 out a lens. These ripple-marks are constant enough in stems of 

 considerable thickness to serve as a valuable diagnostic feature. In 

 some woods pit-areas on the fibres are in seriation ; and in some 

 instances, also, the cells of the wood-parenchyma strands are arranged in 

 a secondary seriation, visible under a lens. The writer appends a table 

 giving for each wood the various elements storied, the uniformity and 

 distinctness of the markings, and the height of the tiers. The storied 

 structure is found also in the secondary phloem. A. B. R. 



