594 Transactions of the Boijal Society of South Africa. 
Although this investigation is still far from complete, it seemed advisable to 
publish a preliminary account of certain of the facts observed. 
Material, of the cleistogamous form only, was collected in the Knysna 
district on several different occasions. The spikes have usually from three 
to seven flowers, but single-flowered spikes are infrequently found. The largest 
specimen examined was nine-flowered. In colour the perianths vary from 
pale green to yellow flushed with orange. Young specimens are readily 
confused with buds of Pterygodinm catholicum, often found growing in the 
same situations. As the buds swell, the difference between the two species 
becomes more apparent, but even in the early stages the powerful almond 
scent of Pterygodium Newdigatae is very distinctive. 
I have examined some hundreds of flowers and noted considerable varia- 
tion in the inner perianth lobes. A large percentage of specimens received 
from Knysna on November 9, 1914, had one or occasionally both side petals 
well developed, and of a deeper yellow colour and more delicate texture than 
other floral parts (Figs. 2-5). A thickening at the base of the labellpm was 
of fairly frequent occurrence (Figs. 7-9). The closest approach to the 
perianth of the chasmogamous form was observed in a single-flowered 
specimen received on November 20 (Figs. 6, 10, 11). The parts, which 
were at first united, sprang apart during the handling of the specimen, 
disclosing a column of abnormal form (Figs. 12, 13). 
The column in the cleistogamous variety is exceedingly variable. Dr. 
Bolus figured three distinct forms ; I have examined some 500 flowers and 
noted the following varieties : 
(a) Eostellum arms 2, undivided ; column occasionally symmetrical 
(Fig. 14), but more frequently showing a difference in length, breadth, or 
curvature of the arms (307 examples). 
(h) Kostellum arms 2, variously lobed or divided. The lobing may 
affect the sterile tissue only, or the fertile tips, or both (Figs. 15, 16) 
(75 examples). 
(c) Rostellum arms 4, undivided. As a rule the two pairs of arms are 
somewhat widely separated (Figs. 17-20) (48 examples). 
(d) Eostellum arms 4, variously lobed or divided (Fig. 21) (17 examples). 
(e) Kostellum arms 3, contorted or slightly lobed (Fig. 22) (12 examples). 
(/) Extreme abnormalities (Figs. 23-25) (22 examples). 
The drawings give some idea of the enormous variation of the column 
met with in this Orchid, which is in striking contrast with the conservative 
character of the essential organs in allied species and throughout the entire 
order. 
The two-armed form is by far the commonest, but does not seem to have 
been represented in the material examined by Dr. Bolus. Further develop- 
ment and branching of this form may have given rise to the variations 
noted above. 
