124 BRITISH PLANTS 
about destructive changes of any kind in organic matter. 
All plants, green or not, if supplied with sugar and the 
proper mineral salts, can build up proteins, so there is 
no reason why the proteins required by saprophytes for - 
their nutrition should be obtained in the same way as 
the carbohydrates. Saprophytes, as a rule, make their 
own proteins, but most of the nitrogen required is ab- 
sorbed in the form of ammonium-compounds, in which 
humus is richer than in nitrates. At the same time, there 
is little doubt that proteins, if present, are also absorbed 
and utilized in the economy of the plant. 
(i.) Total Saprophytes.—There are very few total 
saprophytes among the higher flowering plants in this 
country, and a curious feature in 
them all is that they do not absorb 
the products of decay from the 
humus directly, but through the 
/) intervention of a mycorhiza, a sub- 
ject-fungus which inhabits the roots 
or stems, and replaces the root-hairs 
of the higher plant (Fig. 39). The 
British flowering saprophytes are: 
Neottia Nidus-avis, the bird’s-nest 
orchid, a leafless saprophyte, fre- 
quently occurring in the humus of 
moist woods, especially under old 
beeches and in hazel-copses. 
Monotropa Hypopitys, the yellow 
TS tha (Mac. bird’s-nest, a saprophyte with scaly 
NIFIED.) leaves found occasionally in the 
humus of fir, beech, and birch woods. 
Corallorhiza innata, the coral-root, a very rare sapro- 
phytic orchid found in boggy woods. It has a much- 
branched fleshy rhizome, but no roots (Fig. 40). 
Epipogum aphyllum, a yellow orchidaceous plant, 
possessing neither leaves nor roots. It has been found 
only once in this country. 
Saprophytes are all descended from green ancestors, 
but owing to their mode of life the presence of chlorophyll 
is rendered unnecessary, and it has disappeared; the 
leaves, not being required for purposes of nutrition, have 
degenerated into scales or vanished altogether. The 
chief factor in their degeneration has, no doubt, been the 
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