250 MB. H. N. Ridley's mon-ogbaph 



the seeds upon other and lower branches of the trees on which 

 the plants grow, in the case of the marsh-loving species, were the 

 seed-pods to be recurved, there would be considerable risk of the 

 seeds falling too close to the parent plant. 



Fertilization. — I cannot find that, with one exception, any 

 observations have been published upon the fertilization of any 

 species of the genus. Mrs. Barber ( Journ. Linn. Soc, Bot. x. 1869^ 

 p. 455) suggests that small Hymenoptera or Diptera might be the 

 impregnators of L, BowTceri^ Harv., which species she cultivated in 

 her garden in South Africa, but found them not fertilized there. 

 She remarks that she never found any honey in the blossoms ; 

 neither have I been able to detect any in any of the species 

 which I have been able to examine in a livinoj state. The 

 flowers do not appear as a rule to have any scent ; but X. lonppes 

 is an exception, it has an unpleasant odour. Notwithstanding 

 this, they seem to be in some way attractive to insects, as I have 

 seen ants busily running about upon the lip of L. Saundersiana^ 

 Heichb. f., as if there was something there worth seeking. 



The insect attractions to the plant are of three kinds. In plants 

 of the Zf. longipes type there is a smooth polished band of a 

 darker green than the rest of the lip running for the whole 

 length of the labellum, very similar to that which occurs in the 

 lip of Listera ovata, R. Br. The lip in these species is so curved 

 that its highest part is immediately under the anther, so that an 

 insect alighting upon the apex of the lip and creeping up would 

 strike with its head the anther and receive the poUinia. In some 

 of the larger-flowered plants, in which this would appear to be 

 the means of fertilization, there is an ochreous or orange patch 

 in the centre of the lip (L. reflexa, E. Br., L, Uciniata, Eidl.). 

 In another series of plants the veins at the base of the lip are 

 thickened, and sometimes {L. neuroglossa, Eeichb. f.) brightly 

 coloured. These doubtless are attractive to insects ; and once in a 

 flower of L. elliptica, Eeichb. f., from Venezuela, I found the base 

 of the lip had been gnawed by some animal, and there were a 

 pair of pollinia lying in the stigma. This, however, may have 

 been accidentally done in pressing the flower. 



A considerable number of species, again, have these veins raised 

 at the extreme base of the lip into two conical calli. In this case 

 the lip usually, as stated above, has a distinct channelled claw 

 and a broad deflexed lamina ; sometimes there is only one callus, 

 which is in some cases notched at the apex, from which it appears 



