320 ANNUAL REPORT SMITHSONIAN INSTITUTION, 195 4 



they are used as ornaments. The rosary pea (Ahrus precatorius) (pi. 

 3, fig. 10), another bean from the Tropics of Asia has a hard, scarlet 

 coat with a black spot. These beans are used extensively in the Tropics 

 for beads, rosaries, and other ornaments. The powdered seeds made 

 into a paste and applied to arrows or darts make any wound fatal in 

 about 24 hours. Seeds of the strychnine tree {Strychnos nux-vomica 

 L.) (pi. 2, fig. 9), native of India and Indochina, are disk-shaped and 

 about an inch in diameter. These seeds yield the very poisonous sub- 

 stance known as strychnine, which is of importance medicinally. An- 

 other species of Strychnos, native of South America, yields curare, 

 a deadly poison used by natives for poisoning arrows, and now coming 

 into importance in modern medicine. 



The dye known as annatto, from the "lipstick plant" {Bicca orellana) 

 (pi. 3, fig. 12), used in the coloring of oleomargarine, is a tropical 

 American species. The dye is made in the outer soft, red layer seen 

 in the illustration. This layer is an extra seed coat which is found 

 in some species and is known as an aril. The spice known as mace 

 is from the aril of the nutmeg seed. The edible part of the Chinese 

 fruit called the litchi is the fleshy aril. Another seed with an aril 

 (pi. 3, fig. 13) is from the bird-of-paradise-flower {Strelitzia nicolai) 

 a mat of tangled orange-colored hairs which grow at one end of the 

 seed; and another is the seed of the traveler's tree {Ravenala mada- 

 gascariensis) (pi. 3, fig. 14), with the membranous, metallic-blue aril 

 enfolding the seed. This metallic-blue pigment is unusual among 

 plants. These last two species belong to the banana family. In nei- 

 ther case are the arils of any use to the plants, yet they continue to 

 develop on each new crop of seeds and from generation to generation. 



Seeds may vary through outgrowths from the seed coat, forming 

 wings, spines, and hairs. The cotton seed (pi. 4, fig. 17) is an extreme 

 example, with long hairs growing from the entire surface of the seed 

 coat. These hairs certainly have no survival value to the cotton plant ; 

 in fact they are a disadvantage to distribution of the seeds in the wild 

 state. There are many varieties of cotton {Gossypium) derived from 

 indigenous species from both the Old and the New World. It is 

 known that some Peruvians were cultivating cotton and were weaving 

 textiles from it in 2500 B. C. Most of the cotton in cultivation in 

 the United States is of American origin. These varieties have 52 

 chromosomes while the African and Asiatic varieties have 26 chromo- 

 somes and will not hybridize except on rare occasions. Because of 

 this the Old and New World types have remained distinct even though 

 they were brought together in our southern States in the earlier periods 

 of cotton culture. Although the species of the two types will not 

 readily cross, the hairs or fibers from the seed coats are very similar. 

 It is remarkable that widely separated primitive peoples of the two 



