BY A. G. HAMILTON. 765 



colour. The filaments are about 1 mm. long out of the tube. 

 The stigma is red. I have seen a head visited by small insects, 

 either flies or bees, but they were so rapid in their movements 

 that I could not determine which. 



ASCLEPIDIACE5:. 



Marsdenia flavescens, Cu7in.—The individual flowers are 

 small] and dull-coloured, but as they grow in large and close 

 umbels they are on the whole conspicuous. The scent is very 

 rich and strong; and they produce abundance of honey. They 

 are frequented by various species of flies, bees and butterflies, the 

 latter almost always belonging to either the Lycsenidse or the Hes- 

 peridfe. I have not observed in any of the visiting insects the 

 pollinia attached, and the plant does not fruit freely — three or 

 four per cent., at most, of the flowers setting seed. A plant well 

 in flower is a good lure, and the butterfly collector will find a 

 visit to such on a warm day well repaid. 



LABIATiE. 



Plectranthus parviplorus, Henck. — The flowers are arranged 

 in fours like whorls, in a spike. The upper lip has three or four 

 lobes; the lower lip is entire and deeply concave. The colour is 

 purplish-blue and the flowers are sweet-scented. The stamens 

 are four, two long and two short. They are mature before the 

 stigma. When the flower opens the anthers are bent upwards 

 above the concave lip (fig. 9), while the style with its as yet 

 unopened stigma lies at the bottom of the concavity. Insects 

 visiting the flowers at this stage take up pollen on their under 

 sui'face. When the anthers have discharged all their pollen they 

 bend down into the cup of the lower lip, while the style bending 

 upwards takes their place, the stigma opening at the same time 

 (fig. 10). In this stage the stigmas rub against insects and, 

 taking up the pollen, are fertilised. The insects seen visiting are 

 Taractrocera pajjyria, Boisd., and Lyccena Inhradus, Godt. The 

 plants seed very freely. They flower almost all the year round. 



The flower stalks, peduncles and calyx are closel}^ covered with 

 trichomes of two forms (fig. 11). 



