230 MR. R. A. ROLFE ON THE APOSTASIEX. 
In the Suborder Monandre the median stamen of the outer 
whorl is alone normally perfect (though others are occasionally 
developed in monstrous flowers) ; and the pollen-grains are united 
together in tetrads, or variously aggregated in masses *. And cor- 
related with this greater complexity in the staminal characters is 
very frequently a high degree of specialization in the other parts 
of the flower. 
Tribus 1. ArostasıEz, R. Br. in Wall. Pl. Asiat. Rar. i. 
(1830), p. 74. Ovarium perfecte triloculare placentis axilibus. 
Perianthium subregulare. Columna brevissima. Anthere bre- 
viter vel plus minus stipitate, lineares vel angusti-oblonge ; 
pollen siccum. Stylus plus minus elongatus. 
In the remaining tribe, the Cypripediee, the perianth is very 
irregular; the lateral sepals, with one solitary exception (Cypri- 
pedium arietinum, Ait.), being united into one body, which is thus 
placed exactly opposite the dorsal sepal, and behind the median 
petalorlip. This latter organ is modified into a pouch or slipper- 
like organ, quite different from the lateral petals, which again are 
always more or less dissimilar to the sepals. The column is more 
elongated and curved ; the two perfect anthers globose, while the 
third is invariably transformed into a shield-shaped staminode, 
which partially eloses the mouth of the lip. "The pollen-grains 
are held together by a glutinous fluid exudation, whieh causes it 
to adhere to the bodies of insects, by which means it is carried 
from flower to flower. Lastly, the free portion of the style is 
very short, and terminated by the enlarged oblique stigma. The 
two genera agree in these respects; but while the Tropical 
American Selenipedium has retained the ovarian characters of 
the Apostasiee, the remaining genus, Cypripedium, agrees with 
the Monandre in possessing a one-celled ovary with parietal 
placentation. 
CONsPECTUS GENERUM. 
Perianthium subeonnivens. Stamina 3, omnia perfecta. Racemi 
erecti, simplices. Flores mediocres.. 1. Neuwiedia, Blume. 
* To this Cephalanthera forms a solitary exception, having single pollen- 
grains ; but as the genus is obviously a degraded representative of the Neottiee, 
with which in every other respect it entirely corresponds, it cannot be held to 
invalidate the general correctness of the above classification. 
