A NATURALIST IN BRAZIL 



planted. When a cotton-field is in flower it looks like a field of rose- 

 bushes in bloom — Marechal Niel roses, for instance; for the great 

 mallow-like blossoms of the cotton-plant are a handsome yellow 

 (Plate 25). After fertilization the petals of the flowers fall; the seed- 

 capsules or pods, to which the involucral bracts are still attached, 

 grow bigger than a walnut, and assume a pointed form (Fig. 9). In 

 the compartments of this green capsule are the seeds, covered with 

 a thick felt, and surrounded by the long, white, tangled seed-hairs. 

 These hairs are the cotton; when the capsule is ripe, and the five 

 valves of its green shell spring apart, the cotton protrudes like a 

 dense ball of wadding, while the capsule turns brown and withers. 



In this condition the cotton is 

 plucked and taken to the factory, 

 where the fibres and seeds are 

 separated by means of special 

 machinery. Oil is pressed from the 

 seeds. 



Cotton played a special part in 

 connection with my Brazilian 

 journey; for the pest which attacked 

 the plantations was the cause of 

 the invitation which I received 

 from the Government of the State 

 of Pernambuco. This pest is a 



Fig. 9.— Sprig of cotton-plant, with moth, which lays its eggs on the 



flower, capsule, and ripe, open underside of the leaves, or on the 



capsule, from which the cotton is flowers or young capsules. From 



protruding (reduced) , , -n 



^ the egg emerges a caterpillar, 



which on account of its rosy colour is called the Rosy Caterpillar 

 (Lagarta rosada). It bores its way into the capsule, and eats into its 

 heart, with the result that the white cotton is transformed into a 

 black, earthy pulp, while the valves of the capsule spring open 

 prematurely. 



The Rosy Caterpillar comes from India, where, however, it did 

 little harm to cotton until American varieties were introduced. 

 Thus this pest confirmed the experience of ages, that two forms of 

 life which have evolved in the same country do not upset the 

 equilibrium of Nature, but that the existence of a plant or animal 

 is first endangered when it is confronted by an alien enemy. The 

 same thing occurred in the case of the Phylloxera, which did no 

 harm to the American vines, for these had evolved beside it, and 



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