Rhodesian species of Fuirena , Hesperantha ) and Jttsticia . 197 
in the unprotected stomata, which suggest a shade habit. The hereditary 
organization of the plant, which enables it to form the epidermal water- 
jacket and dorsal stomata, has proved sufficiently plastic to meet altered 
conditions. Aerial exposure to intense illumination and intermittent 
dryness is made possible by materially increasing the size and volume of 
the water-cells on the exposed surface of the leaf, and a satisfactory 
adaptation to present environment is thus secured. 
Where the aerial stem bears rather broad leaves with moderately well- 
developed lamina and is exposed to constant xerophytic conditions, we find 
the modifications more complete, and in F. sub-digitata we get the protected 
and sunk stomata and an increase of water-tissue which replaces the air- 
canals. In F. stricta on the contrary, where the leaves are fewer and the 
laminae very much reduced, beyond a slight sinking of the stomata and 
the reinforcing of the water-sheath by a strong sclerotic one, the hereditary 
organization of water-jacket and papillose cuticle has proved sufficient. 
Hesperantha matopensis Gibbs. 
This Iridaceous species was found growing amongst grass on the sandy 
banks of a stream, which had cut a channel through the sand a metre below 
the level of the veld. It was in flower and leaf in September, before any rains 
had fallen, after a period of five months’ drought. The flowering scape was 
on a level with the surrounding yellow grass haulm, which the flowers, that 
only opened at night, rather resembled in their light straw-brown colour. 
Towards evening the perianth segments would reflect, exposing the style 
and stamens, and a delicate perfume was emitted. 
The interest of the plant centres in the extraordinary development of 
the tunics in comparison with the minute size of the corm to which they act 
as a protective covering. The corms with the tunics are from 12 to 1 5 cm. 
long and 14-18 cm. broad ; but the actual corm itself only measured 5 mm. 
in length and 8 mm. in breadth, the difference in size being accounted for 
by the old scale-leaves of each year’s successive growth persisting as rings 
one inside the other, round the corm. 
The morphological development of these scale-leaves, of which one 
only is produced every year, is very interesting and obtains throughout this 
genus and the allied genera of Lapeyrousia and Geissorhiza in varying degrees 
of complexity, but Hesperantha matopensis^ as compared with material in 
the British Museum and at Kew, apparently shows the most extreme form. 
The scale-leaves are symmetrical in form, flattened at the base, dark 
brown in colour, and of a hard, smooth consistency. They are split about 
a third of their length into longitudinal segments with laciniate margins 
(Text-fig. 1, t) due to a folding of the scale-leaf tissue, the split occurring 
up the centre of the fold. At the base round the flattened portion of the 
