A NATURALIST IN BRAZIL 



scrambling down with the rotting boughs on which the Orchids were 

 growing.) 



Tuberose, vanilla, lily of the valley, rose — every kind of scent is 

 emitted by the Orchid family, from the faintest aroma to the 

 stupefying fragrance of the American Stanhopea. And not only 

 butterflies, bees, and beetles are attracted, but flies as well, for the 

 Orchids which have need of them taint the air with the stench of 

 goats or of carrion. 



Once the insects have entered the cloud of perfume and fly 

 towards its source, they cannot miss the brightly-coloured flowers 

 which have summoned them. There are few flowers which give such 

 an impression of oflfering themselves in generous surrender as the 

 Orchids. With their strikingly shaped and coloured petals they seem 

 to wave to us as though with wings, and from the widely-opened 

 blossom the "underlip" is protruded, covered, as a rule, with 

 hairs, as a convenient alighting-place (Fig. 14). As we shall see in 

 Chapter XIII, ihe Orchids are fertilized by insects, for the latter 

 convey the male pollen to the female stigmata. 



When fertilization is accomplished the petals fall, and the fruit 

 develops, in the form of an elongated capsule. During the dry season 

 this capsule opens, the seeds fall out, and are borne away by the 

 wind. Many of the Orchids have developed a special device in the 

 capsule which prevents the seed from falling out in damp or rainy 

 weather, when the wet seed would drop to the ground. In these 

 capsules the seed is surrounded by a sort of felt, consisting of very 

 fine hairs. These are so constructed that they absorb the moisture 

 in the air, and at the least increase of humidity they twist themselves 

 and curl up in the most curious fashion. When a dry wind opens 

 the capsules the hairs begin to fluff' themselves out, expelling the 

 seeds lying among them, which are then carried off" by the wind. 

 In damp weather the capsules close, and the hairs and seeds are 

 imprisoned. 



For a long while attempts were made to raise the magnificent 

 tropical Orchids from seed in our European hot-houses, but when the 

 seeds were sown in earth they failed to germinate. A French botanist 

 was the first to solve the puzzle. For its germination the seed of the 

 Orchid needs the help of a tiny fungus, which is found, like a 

 microscopic network, wherever Orchids grow. The seed of the 

 tropical Orchids germinate only if laid upon orchid mould, or on soil 

 which contains such little fungi. On germination a minute green 

 nodule appears, as transparent as glass, which takes hold of the soil 

 104 



