514 



SCIENCE. 



[N. S. Vol. I. No. 19. 



belong to sixty-seven families, the leading 

 ones including nearly one-half of the species, 

 being Papillionacese, MjTtacese, Eubiacere, 

 Lauracese, Artocarpacese, Cesalpinaceffi, 

 Euphorbiacete, Meliaceje, Mimosacese and 

 Anonacese. The individuals of a species 

 are widelj^ scattered and it is often difficult 

 to find more than one or two of a kind. 

 The great number of species is attributed to 

 the uninterrupted development of the forest 

 during many geological ages, the campo- 

 growths being a derived and more recent 

 flora. The height of the trees is rarelj^ more 

 than 20 to 25 meters. The trunks are not 

 scraggy like those of the campos, and the 

 bark is smoother and less corky. The well 

 lighted forests have a dense undergrowth of 

 shi'ubs 1-3 meters high, most of which bear 

 small white flowers. The soil of the forests 

 is poor in herbaceous and suffrutescent 

 species. There is no carpet of mosses or 

 lichens. Agarics are small and very rare. 

 Grasses form no part of the covering of the 

 soil, and if any exist in the forest they are 

 tall perennials such as Olyra and Bambusa. 

 The forest is rich in climbing and twining 

 plants, in striking contrast to the campos. 

 The big woody lianas belong principally to 

 Bignoniacese, Convolvulacese, etc., and the 

 herbaceous climbers to Cucurbitacese, Passi- 

 floracese, etc. The Convolvulaceie of the 

 forests are generally voluble, while those of 

 the campos are erect under-shrubs. The 

 numerous Aristolochias of the forest are also 

 all voluble, while the single species of the 

 campos is an under-shrub with stems 15-30 

 centimeters high from a woody, tuberous, 

 subterranean axis. The air is so dry that even 

 in the forests there are but few Epiphj'tes. 

 Cactacese and other fleshj^ plants, and num- 

 erous hairy, thorn j' and stinging plants grow 

 in the more open forests on the calcareous 

 rocks. 



Only the forest lands are used for agricul- 

 tural purposes. The trees are felled, and 

 after the clearing has been subject to the 



heat of the drj' season for some months it is 

 fired and then planted — sometimes to sugar 

 cane and rice, but more generally to Indian 

 coi"n, with castor bean, perennial cotton, 

 beans, cucumbers, pumpkins, etc., between 

 the hills. After the second year the clear- 

 ing is abandoned. These neglected clear- 

 ings are soon covered with a dense growth 

 of weeds, which are quickly crowded out 

 by various shrubs — felted leaved and spiny 

 Solanums, hispid Lantanas, dirty green or 

 brown hairy Crotons, numerous Sidas and 

 other Malvaceae, dull composites often stickj', 

 tall grasses Mdth large leaves and many 

 other plants, mingled with which are shoots 

 from the tree stumps. Graduall}' the area 

 becomes once more a forest, twentj^ or thirtj' 

 years sufficing. It is said that after the 

 forest has been cleared awaj^ three or four 

 times it will not return, its place being 

 taken by bushes, thickets of Pteris aqui- 

 lina var. esculenta and dense masses of the 

 glandular hairj' Panicum Melinis ; 43% of 

 the weeds of the gardens and clearings are 

 annuals, and a few of these weeds are old 

 acquaintances, e. g., Chenopodium ambro- 

 sioides, Gnaphalium purpureum, Xanthium 

 Strumarium, Erechthites hieracifolia, Sou- 

 chus oleraceus, Panicum sanguinale, Eleu- 

 sine Indica, Argemone Mexicana, Phyto- 

 lacca decandi-a, Portulacca oleracea, Phys- 

 alis pubescens, Datura Stramonium and 

 Solanum nigrum. 



The flora of the forest is twice as rich in 

 species as that of the campos. Of the 755 

 genera observed at Lagoa Santa 82 belong 

 exclusively to the campos, 61 are tributary 

 to the water and 364 belong to the forests, 

 although the latter otAj occupj^ a small part 

 of the eountrj\ The forest flora is probablj' 

 much more ancient than that of the campos. 

 Compositse and Papilionacese form about 

 one-quarter of the entire flora of the campos. 

 The flora of the forest is made up chiefly of 

 Compositaj, Polypodiacepe, Orchidaceas, Eu- 

 biacese and Euphorbiacete. A large num- 



