254 ORR—TRACHEAL TISSUE IN CAPPARIDACEAE. 
similar type of cell is found in the tracheal envelope of Capparts 
xanthophylia, Coll. et Hemsl., but in this species the lignification 
of the anticlinal walls is much more pronounced, and it is difficult 
to determine its features in surface view on account of the 
shallowness of the tracheides. 
In Capparis flavicans, Wall., the tracheides are larger than 
those of the preceding species, and the lateral walls are so 
strongly thickened that in surface view an impression is given 
of a succession of unequal protuberances, projecting into the 
cell cavity. This marked configuration has been indicated in 
the figure below, but in actuality it represents the arrangement 
of the thickening on the surface of the lateral walls. 
I 2 
Fic. 3.—A portion of the tracheal envelope of (1) Capparis micracantha, DC., 
and (2) Capparis flavicans, Wall., in surface view. 
3. The structure of the envelope represented in Capparis 
flexuosa, Blume, is almost identical with that of Apophylium 
anomalum, F. Muell. Both are composed of the same shallow 
type of tracheid with delicate spiral bands of the “ spinosa ”’ 
type on the lateral walls. 
Apophyllum, F. Muell. 
In this somewhat anomalous genus, represented by one 
species, the structure of the envelope surrounding the embryo 
closely resembles that found in Capparis flexuosa, referred to 
above. The lateral walls of the shallow tracheides are streng- 
thened by fine spiral bands, and the whole sheath is mainly 
distinguishable from that of its Capparis prototype by the 
more rounded outline of the constituent elements. In general 
configuration it also approximates to the envelope of Maerua, 
from. which it differs, however, in havi ing only one layer of 
tracheides. 
