THE NATURAL HISTORY OF THE FLOWER. 287 
1s perhaps somewhat strange ; though Coryanthes, a near relative 
of Stanhopea, is equally extraordinary in its mechanism. It may 
be hoped tbat some botanist visiting Mexico will study the flower 
there and complete its elucidation. 
Stanhopea tigrina is an epiphytic orchid with enormous pen- 
dulous flowers *. In greenhouse specimens they emerge through 
the bottom of a hanging basket. If held out horizontally they 
are liable to break off by their own weight. The five perianth- 
leaves, other than the labellum, are reflexed from their point of 
insertion, and are very conspicuous, as seen from the side or from 
below. They are of a deep chocolate-red colour striped with 
pale lemon-yellow, and are of a slightly fleshy texture. The 
labellum and column hang downwards, making a curious cage 
(Pl. XVIII. fig. 5); they are very thick and fleshy, and are, in 
consequence, very rigid and elastic. As seen in side view the 
flower, taken as a whole, is about 16 cm. deep and 16 em. wide 
across the perianth, but often even larger than this. The “cage” 
narrows towards the mouth, where the anther and stigmas are 
(fig. 5). The basal portion of the labellum or hypochil (hyp, fig. 5) 
forms a curious pocket-like organ, widest at its lower end and 
with its mouth facing the column. Between it and the latter 
are wide openings through which an insect can fly into the mouth 
of the cavity. The mouth is bounded by sharply marked ridges 
below and at the sides. The inner surface of the cavity is covered 
with stout hairs of a deep-red colour. 
Below the bucket comes the middle portion of the labellum, 
which consists of a stout horizontal mass of tissue (mes, fig. 5), 
prolonged at the ends into two long bars (f,,) which run down- 
wards from it, at first outwards then inwards: these form the 
sides of the cage. The distal part of the labellum is fastened to 
the middle part by a well-marked joint or thin line ; but if it be 
bent at the joint, breakage occurs: the joint would appear thus 
to be merely a survival from jointed ancestors with more flexible 
labella. This part of the labellum is of a broad oval shape, with 
a deep groove in it near the apex ; like the rest of the labellum, 
it is thick and fleshy. The colour of the labellum is a pinkish 
white, with spots of a chocolate colour. 
The fourth side of the cage is formed by the column, a very 
rigid structure (see figs. 5-10). Its basal part 1s nearly cylin- 
drical ; further out it widens into lateral wings, narrowing towards 
* Figured in Bateman’s ‘Orchidacer of Mexico and Guatemala,’ pl. 7. 
Also in Bot. Mag. t. 4197, and Bot. Reg. 1839, t. 1. 
