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follcc we suspect that it is spurred or niuticous in the same spe- 

 cies, though, in the present condition of synonymy, we have often 

 been obliged to accept such modifications as of specific value. The 

 spur itself may be straight or curved or spiral, ascending or de- 

 scending (according to the position of the flower), attenuate or 

 inflated, or clavate or saccate, being sometimes variable in these 

 respects in the same species. 



6. The lateral sepals may be two or four, the two posticous alone 

 (those next the labellum) being invariably present and tolerably 

 constant in form ; the two anticous, first observed by Edge worth, 

 may be present or absent in the same species, and are often reduced 

 to papillae or glands. The apices of the sepals (as of the dorsal 

 spur of the vexillum) are often glandular. The relative size of the 

 sepals and petals offers too often a very fallacious character, de- 

 pending primarily on conditions of flowering. 



7. The form of the flower may be flat — that is, with the laminae 

 of the vexillum, alae, and even of the labellum, all in the same 

 plane; or the whole flower may be concave, from the concavity and 

 prominence of the vexillum and labellum especially, which (as in 

 I. macrophylla) may greatly exceed the alae, and, appearing to con- 

 fine these, give them a vertical direction. 



8. The colour of the flower is very variable in many of the 

 species ; yellow and purple are the prevailing colours, the former 

 passing through ochreous, &c., into a dull red, and the latter 

 through pink, &c., into white. In many, the flowers are spotted, 

 the yellow with various shades of red or purple, and the purple 

 with darker spots or blotches. In I. racemosa and its allies, the 

 yellow and pale purple are mixed, and we find the same species 

 with wholly yellow and with dirty purple flowers. For extreme 

 variation of colour in one species, we would cite /. longicornu and 

 leptoceras ; for intensity of colour, I. janthina and racemulosa. 



9. The inflorescence is always lateral, though apparently terminal 

 in the ScajpigercE and in some of the Bacemoscd. The peduncle is 

 solitary in many, fascicled and axillary in most of the Lateriflorce. 

 The peduncles are 1-flowered in some, 2- or many-flowered 

 in others ; solitary in some, and fascicled in others. The species 

 with normally fascicled 1-flowered peduncles have sometimes the 

 fascicles reduced to one peduncle ; and the species with 2- or more- 

 flowered fascicled peduncles present sometimes 1-flowered fas- 

 cicled peduncles, or even solitary 1-flowered peduncles. This leads 

 to great confusion and an inosculation of some species (or indivi- 

 duals) in all the groups with alternate leaves, which we have been 



