spirally twisted. In other words, M.paludosa has boxed 
the compass with its labellum in what ‘‘nature-lovers’’ 
might regard as a definite effort to accommodate fickle in- 
sects or to attain constancy in pollination through selec- 
tive modifications adapted to insects with a preference 
for a non-resupinate flower. Indeed the labellum is the 
uppermost segment of the perianth because of a twist of 
the pedicel through 860 degrees. With characteristic 
promptness Darwin seized on this peculiarity of the ped- 
icel in M. paludosa to strengthen the ar- 
gument for his theory of natural selection 
and he referred to it as follows: ‘‘in many 
Orchids the ovarium (but sometimes the 
foot-stalk) becomes for a period twisted, 
‘causing the labellum to assume the posi- 
tion of a lower petal, so that insects can 
easily visit the flower; but from slow 
changes in the form or position of the pet- 
als, or from new sorts of insects visiting 
the flowers, it might be advantageous to 
the plant that the labellum should resume 
its normal position on the upper side of  yfajasis satulices 
the flower, as is actually the case with Ma- after Darwin 
laxis paludosa, and some species of Catasetum, &ec. This 
change, it is obvious, might be simply effected by the con- 
tinued selection of varieties which had their ovaria less 
and less twisted; but if the plant only afforded varieties 
with the ovarium more twisted, the same end could be 
attained by the selection of such variations, until the 
flower was turned completely round on its axis. This 
seems to have actually occurred with Malaxis paludosa, 
for the labellum has acquired its present upward position 
by the ovarium being twisted twice as much as is usual. ”’ 
(The various Contrivances by which Orchids are fertil- 
ized by Insects, ed. 2, p. 284) 
[154 | 
