1904] CURRENT LITERATURE 473 
the lime which is deposited between the cells in all of the nodes. The form of 
the genicula are frequently of important taxonomic value and they present several 
types of structure, the pitted structure being described and figured. ‘The pits 
are both lateral and terminal and consist of depressions which extend to the 
middle lamella where there is a lens-shaped thickening which, however, lies in 
the middle of the cavity and does-not completely close the pit—B. M. Davis. 
Miss Forp?° has published a somewhat detailed account of the anatomy of 
Psilotum. The plant is monostelic throughout, being protostelic at the base of 
the aerial stem and often siphonostelic above. In the aerial branches a central 
core of sclerenchymatous fibers is found, and throughout the phloem is poorly 
developed. The form is probably a reduced one, but the anatomical evidence 
does not relate it closely to any of the living Lycopodiales. There is closer 
resemblance to certain Lepidodendron forms; but the combination of sporangial 
, ry . 1 Pap a, «en | , ea | TEs R 
PCE OR IE | OWFR has suovested — 
OO 
4% f sieve tissue in conifers has been studied by CHAUVEAUD,?? 
who describes elements intermediate between sieve tubes and parenchyma occur- 
ring in the hypocotyledonary portions of Abies Pinsapo, though not found in the 
higher regions of the stem. ‘These elements are succeeded by the primary phloem, 
and both are eventually squeezed to a flat mass by growth of the secondary phloem. 
In another paper?’ the same author shows that the double leaf trace in the genera 
Abies and Pinus is single in the leaf of the seedling, and in the course of ontogeny 
splits into two, that is the double leaf trace is a secondary formation.—M. A. 
CHRYSLER. ‘ 
DENNISTON?? finds in developing starch grains of various sorts an outer sharply 
defined layer of material next the plastid which takes up orange strongly quer 
safranin gentian-violet orange stain, while the body of the grain becomes ign 
violet. Grains partly digested by diastase show the orange-staining layer 
affected, while the violet regions are much dissolved and orange-staining materia 
appears in the corroded interior. DENNISTON interprets these pearmanpi — 
that the outer layer is different from the rest (MEYER was able only in a ee : 
to find such a layer in potato starch) and, in harmony ett aaes : ben 
of the developing cell wall, believes it to be a carbohy yet fully poly 
to starch.—C. R. B. 
7 } 18: 
26 Forp, SIBILLE O., The anatomy of Psilotum triquetrum. Ann. Botany 
° 
589-605. pl. 39. 1904 ae 
uvEAUD, G. Le liber précurseur dans le sapin pinsa 
Bot. VIII. 19: 321-333. 1904- 
po. Ann. Sci. Nat. 
, G. Origin 
sapins (Abies) et les pins (Pinus). /. ¢. 335~34°- 
20 DENNISTON, R. H., The structure of the starch grain. 
527-533. 1904. 
Trans. Wis. Acad. 14: 
