307 
Substance in Indigo-yielding Plants. 
In both the young and old leaf an abundant deposition takes place in 
the parenchyma of the mesophyll, the xylem-parenchyma, and in the guard- 
cells of the stomata (Fig. 13). In both the dorsal and ventral bundles 
of fibrous tissue embracing the vascular bundles less occurs, and the same 
may be said of the elements of the phloem ; the epidermis, with the 
exception of the guard-cells already mentioned, contains only traces, while 
the xylem-vessels contain none (Fig. 13 ). 
The pseudo-bulb contains a few vascular strands scattered throughout 
a parenchyma of unspecialized cells containing numerous starch-grains. 
Isolated in this parenchyma and scattered throughout it occur raphide- 
cells. Indigo is deposited throughout the tissues of the pseudo-bulb 
excepting in the xylem-vessels and raphide-cells. 
The amount of blue deposited in the vascular strands both of the leaf 
and pseudo-bulb is small compared with that in the mesophyll. As a 
result of this the vascular bundles appear to the naked eye as white strands 
embedded in a blue matrix. 
V. Phajus Wallichii, Lindl., and Phajus maculatus, Lindl. 
So far as I am aware, the only reference to these two species occurs in 
the article by Goppert on the freezing of plants (3). The aerial vegetative 
organs alone have been examined, and in all respects blue deposition is here 
similar to that in P. grandifolius. 
VI. Calanthe. 
Calanthe was also first investigated by Goppert (3), and, as far as his 
investigation goes, the species of this genus investigated by him agrees in 
all respects with Phajus grandifolius. 
Molisch (5), after an examination of both plants, states for Calanthe 
veratrifolia , Br. : £ Im Wesentlichen Alles so wie bei Phajus 
This is the case, and it is therefore unnecessary to deal with the genus 
at length. Only two species have been examined — C. vestita, , Lindl., and 
C. Veitchiiy a cross between C. veratrifolia , Br., and C. rosea, Benth., in both 
of which species only the aerial vegetative organs have been subjected to 
the test. 
Among other indigo-yielding plants which have been previously 
examined, but of which material has not been forthcoming for the present 
examination, are, Marsdenia tinctoria , R. Br. (5), Echites religiosa , T. and B. 
(17), Wrightia antidysenterica , R. Br. (17), and Crotalaria sp. (17). 
VII. Strobilanthes flaccidifolius, Nees. 
This member of the Acanthaceae is largely cultivated in Assam for its 
indigo-yielding properties. A general account of it occurs in Watt’s- 
