A NATURALIST IN BRAZIL 



Bromelias are to-day — for we find as many species on the ground 

 as in the trees — and rooted in the ground, as are all our European 

 Orchids. Schimper has observed that only a few families of plants 

 have yielded epiphytes, but that these families have produced quite 

 a considerable number. Foremost among them are the Ferns, the 

 Orchids, the Bromelias, the Araceae, the Gesneriaceae (relatives of 

 the Gloxiniae), and the Vaccinaceae (relatives of our Bilberries). 



First of all, the plants must be able to reach the boughs of the 

 trees. On the thatched roof of a labourer's cottage we often find 

 quite a number of plants of different species, whose seeds are pro- 

 vided with the means of floating in the air. But a thatched roof has 

 a large surface, and retains a flying seed without difliculty; the 

 branch of a tree, which is often smooth, is a very different resting- 

 place ; yet it is necessary for the seed to adhere to it. 



There are consequently epiphytes whose seed is contained in a 

 berry which is eaten by birds or monkeys. The seed is voided, and 

 adheres to the bough with the excrement in which it is contained, 

 and which protects it from desiccation. This is the case with many 

 of the Araceae, Bromeliaceae, Gesneriaceae, and other plants. Or the 

 seed may be equipped with hairs which wrap themselves round the 

 branch, or the plant itself may be so thready in form that it may 

 be seized by the wind and cast against a bough, round which it 

 coils like a bola or native lasso. As we shall see, the Greybeard 

 Bromelia behaves in this fashion (Fig. 7). 



Lastly, the seed may be so small that it blows away like dust, 

 and lodges in the chinks of the bark. Such minute seeds have enabled 

 the Orchids to people the trees, and of the 15,000 species of this 

 order more than half have become epiphytes. It has been calculated 

 that a single seed of one species of Orchid weighs only two-millionths 

 of a gramme, and that of another species one two-hundredth of a 

 milligramme. This minuteness has a second advantage : the seeds 

 are produced in great numbers, which increases the probability 

 that at least one seed may reach a suitable position. Even our 

 Spotted Orchis produces 180,000 seeds. 



The Orchids, from our human point of view, stand at the highest 

 point of a process of evolution which has constantly been producing 

 fresh and attractive combinations of colour, scent, and artistic form. 

 Many botanists also place the Orchids at the end of the vegetable 

 system, as they now, reversing their earlier decision, place the plants 

 102 



