Royal Institution of Great Britain. 123 



Martaban, the pitchers are in the form of large yellowish-green bags, 

 hanging in bunches from the slender woody stems by which the 

 species climb to the tops of trees ; and in Marcgraavia umbellata, 

 and in the genus Norantia, the former a West Indian climbing plant, 

 the latter small trees found in the midst of rocks and mountains in 

 Brazil, especially in the Minas Geraes and Serra Dorada, the 

 pitchers are small, coloured, hollow bodies, occupying the place of 

 bracteee, and hanging down or standing erect among the flowers. 



These forms of pitchers were illustrated by highly magnified 

 drawings, and by beautiful specimens furnished for the occasion by 

 Dr. Wallich. 



With regard to the uses for which these curious organs are 

 destined, it was observed that a variety of opinions had been enter- 

 tained, among which it was difficult to say which was most unsatis- 

 factory. Thus Rumphius supposed that the pitcher of Nepenthes 

 was intended as the nest of a sort of shrimp frequently found in it; 

 Morison considered it in Sarracenia as an * operculum divina pro- 

 ' videntia ad obtegendam et defendendam plantam a pluviarum 

 ' injuriis statutum." Linnaeus compared Sarracenia to a water-lily 

 growing in dry ground, and thought its pitcher was a reservoir of 

 rain ; and he supposed that in Nepenthes the pitchers were reservoirs 

 of water, to which animals might repair in time of drought, their lid 

 being especially destined to close up the mouth of the vessel, and 

 thus to prevent evaporation. Sir James Smith thought that in Sar- 

 racenia the pitcher was intended for an insect-trap, because insects 

 are often found in the water, and because the stiff inverted hairs 

 that line it are peculiarly well adapted to prevent the escape of 

 insects once inclosed in it ; and that the putrescence of the insects 

 was converted into the food of the plant. 



The objections to these theories were obviously, that they either 

 depend upon data which are actually false, as in the case of Linnaeus, 

 when he fancies that a plant which really grows in marshes is a native 

 of dry situations ; and that a lid, which never alters its position when 

 once raised from the pitcher, has a power of contracting and closing 

 up the mouth to prevent evaporation ; or else upon unsupported 

 hypothesis, as in the case of Smith's opinion, that the putrescence of 

 insects generates food for the plant ; and of others who think that 

 the pitchers are reservoirs of water for the use of animals in dry 

 weather. With regard to this latter supposition, it was remarked 

 that, in Sarracenia, the water could not easily be emptied out of the 

 pitcher except by birds ; that in Nepenthes it evaporates, without 

 being renewed, shortly after the elevation of the lid ; that in Dis- 

 chidia and Norantia it is not easy to conceive how the pitchers can 

 be emptied at all ; and, finally, that it is contrary to reason to sup- 

 pose that Providence should make provision for an accumulation of 

 water for the use of animals, exclusively in those places where, in 

 consequence of the humidity of the atmosphere, or the nature of the 

 marshy soil, such an accumulation would be of no use. 



