178 ORCHIDACE/E. [Endogens. 



account of the production of Monachanthus viridis, Myanthus barbatus, and a Catasetuin, 

 3 supposed genera, upon the same spike ; and he expressed his opinion that the Catase- 

 tum was the female of these, because he found it producing seeds abundantly, while 

 Monachanthus was uniformly sterile. 



Afterwards a similar specimen made its pp 



appearance in the garden of his Grace 

 the Duke of Devonshire at Chatsworth, 

 and has been figured in the Botanical 

 Register, fol. 1951. And still more 

 lately two' species of Cycnoches, ventri- 

 cosum and Egertonianum have appeared 

 in company, as represented in the accom- 

 panying figure (CXXII.) 



Such cases shake to the foundation 

 all our ideas of the stability of genera 

 and species, and prepare the mind for 

 more startling discoveries than could 

 have been otherwise anticipated. 



If the accompanying diagram be com- 

 pared with those employed to illustrate 



the distinctions of Marants and Gingerworts, p. 169, the relation borne to those 

 Orders by Orchids will be distinctly seen. In the diagram the parts are arranged 

 as they are in nature before the ovary twists ; that is, with the lip next the axis, 

 or uppermost, and the stamen undermost. Let C, C, C represent the outer series 

 of floral envelopes or calyx, and PP, P, P the inner, or corolla, of which PP is the 

 labellum : then the position of the single fertile stamen will be at S, and the sterile 

 ones at s, s; that is to say, in the situation of the supernumerary petaloid stamens 

 of Gingerworts and Marants, while the second series of stamens, to which the fertile 

 stamen of these Orders belongs, is not developed in Orchids. 



In the last edition it was suggested that although this is the apparent structure 

 of the Order, it is not improbable that the parts called sepals are the true petals, 

 because Epistephium and others have a calyculus exterior to the apparent calyx. 

 In that point of view the apparent petals would be sterile stamens, as among the 

 Marants ; it has, however, been shown by Criiger that the order of development of 

 the floral organs of Epistephium is unfavourable to the supposition, and that the 

 calyculus of that genus is in reality a cup-shaped expansion of the ovary. I quote 

 his words from Hcnfrey's Scientific Memoirs, I. 170 : — 



" The development of the segments of the perianth is in agreement with the mode 

 in which they subsequently overlie one another. At each side of the little nodule 

 which is the first representative of the flower of this plant, we observe a little point, 

 the first trace of the sepals, and a little later the middle sepal ; at the same time 

 with the latter, the two lateral inner segments of the perianth. Then the labellum 

 appears, and almost simultaueously with that the anther. In this flower also the 

 anther is at first erect, although it subsequently lies upon the summit of the 

 column. Up to this time no trace of a calyculus is to be seen ; it first presents 

 itself clearly when the flower rises above the axil of the bract, and the boundary 

 botween the ovary and the segments of the perianth becomes visible. The calyculus 

 is persistent upon the fruit, while the other parts separate from it at a very early 

 period. I believe I am justified in concluding from the foregoing, that the calyculus, 

 when it presents itself in the Orchidere, does not represent an external circle of 

 organs, because (1) its segments do not alternate with those of that standing above 

 it ; (2) they originate later than those ; and (3) because they persist upon the 

 capsule, while the other parts become detached. I should lay much stress upon 

 the last reason, yet I think that this calyculus must be regarded as analogous to 

 that which may be observed on the fruits of certain Composita?, Dipsacere, &c." 



In classifying this Order the most important characters appear to reside in the 

 pollen, which in many is consolidated into firm waxy masses of a definite 

 number in each species, and in others is either in its usual loose powdery con- 

 dition, or is collected in granules or small wedges, the number of which is 

 far too great to be counted. Of those with waxy pollen masses some (Malaxes?) 

 are destitute of any visible processes by which the masses are brought 

 into contact with the stigma ; others (Epidendreaj) have strap-shaped cau- 



