1904] ‘ CURRENT LITERATURE 237 
the four cells are always free from air, so that when dry conditions prevail they 
are in a state of complete collapse. ‘The much thickened upper surface of the 
shield part, or Deckel, is the active part concerned in absorption of water from 
the capillary spaces beneath the scale. It is composed of a mesh of cellulose 
containing large deposits of pectin. A layer of pure cellulose covers all. When 
wet, this Deckel absorbs water rapidly, and being resisted beneath by the 
epidermis, as well as on the sides by the cellulose wing of the scale, the only 
direction in which swelling can take place is upwards. As a consequence, the 
Deckel becomes convex, the cone-like processes on its under side straighten out 
and become more obtuse, with the result that the collapsed walls of the four cells 
separate, causing cavities into which water is drawn through thin areas in their 
outer walls, in response to the negative pressure. Water is thus absorbed till 
the scale is distended to its freatest extent, and the four central cells are filled 
with water. Mrz has calculated the amount thus drawn into one scale in Til- 
landsia streptocarpa, and found it to be approximately 0.000464°""™" or 1.451° 
for a given entire plant having 1,880,000 scales. The shield, or central region 
of the scale, lies in connection with a row of 1-4 living cells, which in part form 
the stalk of the scale. The uppermost of these is larger than the others and borders 
directly on the four water-filled cells. The transverse walls of this cell are cuti- 
cularized except in certain small areas. The water contained in the four cells 
adjacent above is drawn through these areas into the cell-by osmotic action due 
to the presence of sugar in the cell sap. 
The water is passed on through the series of stalk cells, whose cross walls 
have uncuticularized areas, till the mesophyll is reached. This continues till 
the water in the capillary spaces outside is exhausted, or until the plant is supplied. 
The water remaining in the four central shield cells is not available to the plant, 
as the tension of the scale overbalances the absorptive power due to osmosis. 
eg must pass off by evaporation from the surface of the scale. It will 
sie, that the scale acts like a suction pump in drawing water into the cells, 
M may be absorbed into the plant by the usual process of osmosis.—F. H, 
on 4 TAXONOMIC INTEREST are as follows: H. and P. SyDOW (Ann. 
establish lade 1904), among descriptions of many new species of fungi, 
‘erocyclus, Phaeodothis, and Maurodothis as new genera of Dothi- 
Gliicacs GREENE (Ottawa Nat. 18:37-39. 1904) in a second paper on 
eins ennarias describes five new species.—T. S. BRANDEGEE (Zoe 5:179- 
as described new Mexican species of Thelypodium (2), Sperma- 
185) h ra aay Castilleia, and Krynitzkia.—J. M. GREENMAN (ibid. ad 
Bapetccin;, as new species of Cerastium (3), Arenaria, Dalea, Nama, an 
other critical : rom Mexico.—KaTHARINE BRANDEGEE (ibid. 189-194), among 
) Blarie otes on Cactaceae, has described new species of Cereus (4) and 
1904), under tig Drets and E. Prirzet (Engler’s Bot. Jahrb. 35:55-160. 
itle “Fragmenta Phytographiae Australiae occidentalis,” present 
