OF CEYLON AND INDIA. 
315 
when the flowers develop. This figure also shows the course 
of the vascular bundles in the thallus. It will be observed 
that there is one to each growing point, and that they unite 
as they pass backwards. The small linear upper sets of 
leaves of each growing point run backwards for some distance 
along the course of the bundles, but at a distance of about 
10 mm. from the tip they have usually mostly fallen ofif, 
though I have occasionally found specimens with leaves still 
visible at 50-75 mm. from the tip. Their somewhat fugacious 
nature, and their small size, is probably the reason why they 
have never been noticed by any one but Tulasne. They do 
not go far enough back to be among the older flowering parts 
which are those usually gathered by collectors. 
The flabelliform type of margin or apex, which has 
just been described for the common Ceylon form (L. z. 
Gardneriana), is not the only one to be found. The other 
Ceylon variety (Parkiniana) has ribbon-like apices, with one 
or few growing points upon them, as figured in PI. IX., figs. 
13, 14. Among the Indian material both types also occur. 
Bearing in mind the form of the apices of the seedling, we 
shall perhaps be justified in regarding this second type as 
the more primitive ; the figure in PI. XII. perhaps represents 
not only the ontogeny of the individual flabelliform. tip, but 
also its phylogeny. The tip of a growing point in material 
from Khandala has been figured by Goebel (13, p. 169) and 
Warming (42, IV., p. 160), and I have verified their obser- 
vations upon material collected by myself. The general 
size of the growing points is somewhat larger, and especially 
the leaves, which, instead of the 2-6 mm. of the Ceylon 
forms, may have a length of 8-15 mm., but the arrangement 
of the parts is similar. Very commonly in these northern 
forms the growing point is turned up clear of the rock, at 
least at the time that it begins to form the flowers, for the 
young stages have not been seen. This phenomenon may be 
simply due to the crowding of the apices together ; very 
often two large lobes of thallus are separated by a kind of 
hedge of leaves due to the erectness of the growing points 
(43) 
