ANGE^CUM. 1 39 



transmission. Since the opening of the Suez Canal, A. sesquipedale 

 has been imported by ourselves and other firms, so that there is 

 now scarcely an orchid collection of note, either in Great Britain or 

 on the Continent, in which it is not represented by one or more 

 specimens. 



The account given by Mr. Ellis to Dr. Lindley of the conditions 

 under which this orchid grows in Madagascar, and published in the 

 Gardeners' Chronicle for 1857, has been transcribed almost as often 

 as the plant has been figured. This account is, however, the best 

 if not the only one known to us, and this must be our excuse for 

 reproducing it here in an abridged form : — 



" It occurs in the lowest and hottest districts, generally on straggling trees 



along the edge of the forest, or in parts Avhere the trees are only thinly 



spread over the country. It grows most frequently on the driest parts 



of the trunks and branches of thinly leaved trees, and occasionally near 



the ground. It grows most abundantly where there is plenty of light 



and air. The leaves are neither numerous nor large, and in its wild 



state the plant most frequently presents a starved appearance and 



straggling habit. The roots are few in number, frequently running 



down the tree on which it grows 12 to 18 feet,* and so tough and 



adhering so tenaciously to the bark that a considerable force is required 



to break or detach them." 



Du Petit Thouars called the species sesquipedale, "a. foot and a half,'' 



in reference to the length of the flowers from the tip of the dorsal 



sepal to the end of the spur. The name doubtless implies a slight 



exaggeration. We know of no instance of which the spur has 



exceeded a foot in length. 



This spur performs the office of a nectary for the secretion of honey. 

 The late Mr. Charles Darwin thence asked, " What can be the use of a 

 nectary of such disproportional length 1 We shall, I think, see (he 

 continues) that the fertilisation of the plant depends on this length, and 

 on the nectar being contained only within the lower and attenuated 

 extremity. It is, however, surprising that any insect should be able to 

 reach the nectar. Our English sphinxes have probosces as long as their 

 bodies, but in Madagascar there must be moths with probosces capable 

 of extension to a length of 10 or 11 inches." He then proceeds to 

 describe the sexual apparatus of the Angrsecum, and tlie contrivances he 

 employed to effect the removal of the pollinia in the same way that an 

 insect Avould withdraw them with its proboscis. The inference he draws 

 from his experiments is perfectly logical, and may be best expressed in 



' ' * See Aiirides, pp. 61, 62. 



