BromeliacecB — Dipsacus. 4 1 



from the centre of this basin, and is thus surrounded 

 with water at its base. Thus the flowers of these plants, 

 which are as a rule gaudy- coloured, nectariferous, and 

 dependent on the visits of flying insects, are set as it 

 were upon an isolating stool; and wingless creeping 

 insects, if they would get at them, must either cross 

 over the water of one of the numerous small funnels, 

 or over the large central basin of the radical rosette ; a 

 task which they naturally will not undertake. How 

 considerable is the quantity of water retained in these 

 funnels may be inferred from the fact that I found the 

 volume of rain-water collected in the central basin 

 of a small Bromeliaceous plant, namely the Vriesia 

 psittacina Morren, at the period of blossoming, to be 

 110 c. cm., and that in the basin oi Billbergiapyramidalis 

 to be 200 c. cm.-' Dipsacus laciniatus L. affords another 

 similar and very striking example. In this plant each 

 pair of opposite leaves are connate at the base, so as to 

 form a funnel-shaped basin which surrounds the stem. 

 Atmospheric deposits fill these basins, and it is aston- 

 ishing how long a time water is retained in them. 

 When no rain had fallen for three whole days I found 

 the larger basins, in a specimen of this Dipsacus, still 

 full of water, the average depth of which was 8 cm., 

 the amount held in one being 180 c. cm. As this 



1 The rain-water contained in the tubular receptacles of the leaf- 

 rosette of ^chmea coendea C. Koch amounted to 215 c. cm., that in 

 a rosette of Lamprococcua Weilbachii Beer to 230 c. cm. 



