Hill ’ — Genus Call ha in the Southern Hemisphere . 425 
In C sagittata , £7. andicola , (7. alata, and (7. invotuta stomata are found 
on both surfaces of lamina and appendage, but those on the lower surface 
are relatively few. Normal spongy parenchyma also occurs and the lower 
epidermis is not specially differentiated. The stomata are also found to be 
more abundant on the appendages than on the laminae. 
In all these southern species the arrangement of the stomata on the 
upper surface is very regular and resembles that of parallel-veined leaves, 
the pores being all set parallel to the midrib. 
In C. limb at a, C. appendiculata , and C. novae-zelandiae , in particular, 
the air-chambers beneath the stomata are remarkably large (Fig. 1 ). 
The vascular tissue of both laminae and appendages is usually well 
developed, and in C. appendiculata , C. novae-zetandiae , and C. obtusa well- 
marked water-pores occur at intervals along the margins of both organs. 
The development of palisade tissue in the Antarctic species is, as 
might be expected, feeble, and in some cases, as for instance in C. limb at a > 
chlorophyll sometimes occurs in the upper epidermis. 
In C. introloba and C. phylloptera, which are mountain plants, there is 
a fairly well differentiated palisade tissue, and in C. alata from the high 
Andes the palisade is very conspicuous and consists of a double or treble 
layer of narrow cells. 
Floral Structure. 
The flowers of these Southern forms do not appear to differ in any 
marked degree from those of the Northern Hemisphere species, the Andine 
species, and also C. sagittata and C. obtusa , having the familiar ovate or 
obovate obtuse perianth-segments and numerous stamens and carpels. 
In C. appendiculata , C. introloba , C. novae-zetandiae , and C. phylloptera 
the perianth-segments are linear-lanceolate or ligulate, and terminate in 
more or less acuminate tips, while in C. dioneaefolia and C. limbata the 
perianth-segments are terminated by somewhat thickened pads of tissue. 
According to Hooker 1 the flowers of C. appendicidata are dioecious, and 
A. Gray 2 refers to this species and also to C. dioneaefolia as being sub- 
dioecious, but these statements cannot be verified from an examination of 
herbarium specimens. 
The carpels are very numerous in some species, especially in C. sagittata , 
and are usually erect when ripe. In C. andicola and especially in C. novae - 
zelandiae , however, they are spreading, and in the latter become almost 
horizontal. 
Whether carpellary nectaries 3 occur in these Antarctic Calthas cannot 
certainly be determined, owing to the difficulty of examining herbarium 
1 Hooker, J. D.: FI. Antarct,, vol. ii, p. 228. 
2 Gray, Asa : Botany U.S. Expl. Expedition, vol. i, p. 13. See foot-note to p. 421 of the present 
paper. 
3 Mueller, H. : Fertilization of Flowers, p. 80, Fig. 27 (Eng. trans.). 
