Ladies' Slippers. 83 



to form a pouch, and in some of the species the pouch so nearly 

 resembles a shoe as to justify the popular likening of it to a 

 "lady's slipper. - " This pouch-like labellum is an essential part 

 of the organic construction, and is directly related to the fer- 

 tilization of the ovary, as Mr. Darwin* has very clearly shown 

 by his original and painstaking researches. In other words, 

 were the pouch modified or removed, the whole plan of the 

 flower, as. respects the disposition of the reproductive organs, 

 would need to be modified also, the mechanical relationships 

 of the several parts being matters of necessity, and every 

 minute detail fitting properly into a complicated scheme. 



But let us glance at the construction in order to obtain 

 some distinct idea of the nature of the demarcation which 

 lends so peculiar an interest to the* study of the ladies' 

 slippers. The plan of an orchid is ternary, and it consists in 

 all of fifteen elementary parts. That we cannot very easily 

 trace these out in any orchid is owing to the fact that some of 

 the parts are commonly confluent, or peculiarly modified, or 

 extravagantly developed, or nearly suppressed. There are 

 three sepals, and these are usually determinable, because 

 usually nearly equal ; three petals, one of which usually gives 

 the flower its most interesting feature, being modified into 

 what is termed the labellum, or lip. There are three stamens, 

 only one of which is commonly developed, and this is confluent 

 with the pistil forming the column. In Oypripedium alone do 

 we find three stamens, and by the aid of this genus, therefore, 

 we obtain a key to one of the life mysteries of this mysterious 

 order. Yet here again ordinary eyesight is baffled, for only 

 two stamens can be found in Oypripedium, and these are placed 

 right and left of the column ; the third is in the customary 

 place between them, but being sterile is not recognised until 

 we have made a careful study of the flower. There are three 

 pistils, but these again are so modified as to require to be 

 discovered in the mind ere they can be traced in the flower. 

 They are, in the first place, united, and confluent with the 

 stamen; the upper stigma is modified into the extraordinary 

 organ called the rostellum, which ordinarily presents no likeness 

 to a stigma at all ; and the two lower stigmas are confluent, 

 and appear as one, and this one occupies a central position 

 below the anther, and is the stigma to which reference is made 

 in descriptions, and to which special interest attaches in respect 

 of the process of fertilization. Lastly, the ovary consists of 

 three perfect carpels, stationed alternately with the stamens 

 opposite the petals, and bearing the placenta in their axes, and 

 of three other pieces, destitute of placentas, and eventually 



* The Various Contrivances by which British and Foreign Orchids are Ferti- 

 lized ly Insects. By Charles Darwin, M.A., F.R.S., etc. Murray, 1862. 



