382 MR. H. H. W. PEARSON ON SPECIES OF 
the difficulty of studying the living plants under natural 
conditions, they should not be disregarded. Such suggestions 
as I shall put forward will, I trust, result in stimulating the 
interest of botanists who may be in a position to confirm or 
disprove them. 
A fairly complete study of the pitchers of D. Rafflesiana by 
numerous investigators leads to the conclusion that they are to 
be regarded as living “ flower-pots.”* They are well supplied 
with a root-system ; they contain usually water and soil. The 
double pitchers undoubtedly serve the same purpose, and my 
object now is to show that they are very specially adapted to 
this end. 
All four species are epiphytes, and probably resemble 
D. Rafflesiana in having an entirely adventitious root-system. 
In addition to the roots already mentioned which branch inside 
the pitchers, they bear others which serve to attach the plant to 
the bark of the host. The latter may be assumed to have also 
an absorptive function as in D. Rafflesiana t. With or without 
dissection, 1 have been able to examine the contents of about 
9 pitchers. They all contain roots in the outer pitcher, but 
nove at all in the inner. In all cases more or less soil} is 
present in the outer pitcher among the roots ; and it seems that 
the greater the amount of soil present, the greater is the 
development of roots in the outer pitcher. Groom believes this 
to be the case in the pitchers of D. Rafflesiana§. It has been 
clearly demonstrated that soil-particles in the pitchers of that 
species are attached to the root-hairs in a periectly normal 
manner ||, and there is every reason to believe that the solids 
form a not unin portant source of the food-supply ot the plants. 
My material being entirely ina dried condition, there is no direct 
evidence as to the presence of water in the pitchers. That the 
roots must be supplied with moisture is obvious. The presence 
of numerous stomata on the inner surface of the outer pitcher— 
* Thiselton-Dyer, Ann. Bot. vol. xvi. p- 369. 
t Groom, Annals of Botany, vol. vii. p. 236. 
{ The term “soil” is used in a wide sense to include the organic 
inorganic débris in the pitchers, the nature of which it is usually impossible to 
determine. 
§ Groom, 2. c, pp- 227, 228. ii 
| Groom, Zc. p. 227, pl. 10. fig. 10; Scott & Sargant, Ann. Bot. vol, vil 
p. 260, pl. 12. fig, 11. 
and 
