XXXVI. — THE BIRD’S-NEST ORCHID. 
Neottia Nidus-avis Richard. 
T HE Family Orchidace <e includes numerous examples of two types of abnormal 
nutrition. Most of the Tropical representatives of the Family are epiphytes , 
attached to, but not nourished by, the branches of trees and getting their food from 
the atmosphere and from accumulations of humus (dead bark and leaves), which often 
collect in large quantities in the shelf-like hollows between the clinging “air-plant ” 
and the branch that supports it. Among the terrestrial Orchids it is probable that in 
many cases there is a symbiosis or partnership with a fungal mycelium or mycorhiza , 
by which the Orchid may be assisted in the acquisition of its necessary nitrogenous 
food-material. An Orchid with green leaves will manufacture its own carbonaceous 
food-material from the carbon-dioxide of the atmosphere, depending on the 
mycorhiza, perhaps, for nitrates. Where, however, as in the Bird’s-nest Orchid 
( Neottia Nidus-avis Richard), the green colouring-matter (chlorophyll) is absent, the 
plant is dependent for the whole of its food-material, both carbonaceous and nitro- 
genous, upon the soil and the organisms in it. It is, perhaps, significant that, whilst 
many of our forest-trees have what is termed an ectophytic or ectotrophic mycorhiza (from 
the Greek e/cros, ektos , outside ; rpocjsrj, trophe , nourishment), such Orchids as that with 
which we are dealing have one which is endotrophic , i.e. the mycelial threads of which 
actually penetrate the roots of the Flowering-plant. The fungus is probably able to 
absorb complex carbon-compounds from the soil and these it can hand on to the 
thin-walled internal cells of its host-plant, though they might be unable to pass 
through the thicker outer walls of its epidermis. Considering how closely the 
adaptations of parasitic plants resemble those of these saprophytes or humus-plants, 
it is not surprising that, until quite recently, these latter were thought to be parasitic. 
Both Sir James Edward Smith and Sir William Hooker are, however, careful to state 
that they could find no sign of attachment between the roots of the Bird’s-nest Orchid 
and those of the trees at the foot of which it may be found. Just as the absence of 
a cambium or growing layer renders grafting practically impossible among Mono- 
cotyledons, so it may be doubted whether there is such a thing as true parasitism 
among Monocotyledons, i.e. a case of a Monocotyledon parasitically attached to 
another Flowering-plant. 
These cases ot abnormal nutrition are frequently accompanied by abnormalities 
or degeneracies in structure, and of this we have an example in those organs from 
which the Bird’s-nest Orchid derives its names. 
A wan, pallid, uniformly light-brown plant, by no means frequent, but found 
generally among dead Beech-leaves on a calcareous sub-soil, Neottia Nidus-avis , as 
Gerard says, 
“hath many tangling rootes platted or crossed one over another verie intricately, which resembleth a crowes nest made 
of stickes,” 
