402 DE. M. T. MASTERS ON THE FLOKAL 



' On the rioral Conformation of the G-enus Ci/pripedium. 

 By Maxwell T. MastJrs, M.D., F.E.S., F.L.S., &c. 



[Read 18th November, 1886.] 

 (Plate XX. and ten Woodcuts.) 



G-EKEEAL CONFOEMATION OF OeCHID PlOWEES. 



The usual conformation of an Orchid flower *, the relative dis- 

 position of its parts, and the general course of their developmeat 

 are so well known that for the present purpose it is only neces- 

 sary to advert to the relatively excessive development of the 

 median petal or lip, and to allude to the construction of the 

 " column " from three, or more frequently from six (potential) 

 stamens arranged in two rows, an outer and an inner, and cou- 

 crescent with three styles. 



According to the plan followed by Darwin f, and now gene- 

 rally adopted, the outer stamens are, for -convenience' sake, de- 

 noted as Ai, A2, A3, the three inner ones being marked by 

 corresponding smaller letters ai, a2, as. Similarly, the carpels of 

 the gyngecium may be marked Gi> G2, Ga. S may stand for the 

 sepals, P for the petals, Pa or L for the median petal or lip, and X 

 for the staminode J. In the great majority of Orchids the outer 

 median stamen Ai, placed opposite the median petal, is the only 

 one that attains its full development. Any or all of the other 

 five may, under exceptional circumstances, be present, either in 

 a perfect anther-bearing state, or more commonly in the guise of 

 petals. Thus, in Odontoglossum crispum I have met with all six 

 stamens fertile and free §. Arundina pentandra is described by 

 Eeichenbach as having five stamens ; and Fritz Miiller mentions 



See Eichler, ' Bluthen Diagramme' (1875), i. p. 179 et seq. ; Gerard, " SaT 

 ITiomologie et le diagramme des Orchidees," Ann. Sc. Nat. Bot. 6^ s^r. t. vin. 

 p. 213, 1878; Van Tieghem, 'Traite de Botanique * (1884), p. 1387, and the 

 same author, *Sur TAnatomie compar6e de la Fleur' (1871), p. 140; Pfitzers 

 • Morphologische Studien iiber die Orchideenbliithe ' (1886) has been issued 

 since this paper was written. 



t * Fertilization of Orchids,' ed. 2 (1877), p. 236. 



J It must be borne in mind that throughout this paper the flower is supposed 

 to be in the adult stage subsequent to any torsion, and that the numbers Ai &C- 

 do not apply to the order or period of development of the several parts. 



§ Masters, ' Pflanzen Teratologic,' ed. Dammer (1886), p. 439, figs- 213, 214. 

 In this edition numerous instances are cited of polyandry in Orchids in addition 

 to those mentioned in the original edition (1869), p. 382. See also Masters, 

 " Orchids single and double," in * Gardeners' Chronicle' (1885), May 5, p. 697- 



