MR. H. BOLUS ON SOME CAPE ORCHIDS. 235 
Lindley separated Herschelia from Disa on account of the 
structure of the rostellum, which he thus describes :—“ Rostellum 
tripartitum, laciniis lateralibus angustioribus acuminatis ; appen- 
dice dorsali, lineari, bilobo, utrinque tuberculato ante antheram 
sito ” (Gen. & Sp. Orch. p. 362). But he describes two glands, 
* glandulis duabus maximis truncatis corneis dentatis.” On this 
account I examined ten flowers; but never found more than one 
gland, nor did I observe any tendency in the gland to become 
divided. Nevertheless, there is some ground for suspicion that 
this character may not be constant. It is much more important 
that Lindley has omitted to notice the bilobed character of the 
stigma, which in this, as in Disa barbata, I believe is constant. 
This omission is to be accounted for by the fact that Lindley had 
very poor material at his disposal. He says himself :—“ The 
structure of the column of this beautiful plant is very singular, 
and not to be well understood without better materials for exa- 
mination than I have procured. A single flower is all that I have 
been able to analyze.” 
I was led to think it probable that the Dise of the section Tri- 
chochilia generally might present similar structural peculiarities. 
But in Disa spathulata, Sw., and D. Charpentieriana, Reichb. f., 
the rostellum is like that of D. grandiflora, and the pollinia termi- 
nate in distinct glands. D. lacera, Sw., and D. multifida, Lindl., 
are probably mere forms of D. barbata, Sw., described above ; but 
Thave had no opportunity of examining authentic specimens. 
A number of specimens of an Orchid sent to me from Port 
Elizabeth, by Mr. J. R. Holland, as Herschelia celestis, exhibited 
the rosteilum and bilobed stigma of that species; but differed in 
the shape of the lateral petals, in the labellum being more or less 
deeply lacerate, and in having two glands terminating the cau- 
dicles of the pollinia. Lindley describes the labellum of Her- 
schelia as quite entire; and that is the case with all the Cape-Town 
specimens I have seen; but I suspect that both the latter cha- 
racters may be variable. 
The presence of caudicles connate in a single gland was relied 
upon by Lindley as the chief distinction of Monodenia from Disa. 
But with it were associated some other minor peculiarities which 
seem to warrant the maintenance of Monadenia ; and it so happens 
that the two Dise noted above as having only a single gland are 
those which least of all in the genus resemble Monadenia. 
Mr. Bentham appears to be of the opinion (Linn. Soc. Journ., 
Bot. xviii. p. 357) that Herschelia should again be included in 
