57 



THE POPULAR SCIENCE MONTHLY. 



teristic animals, and in it white potatoes, tur- 

 nips, beets, the Oldberg apple, and the more 

 hardy cereals may be cultivated with mod- 

 erate success. In the Transition zone, the 

 outlying boreal and austral elements over- 

 lap ; the forests and the fauna are mixed, and 

 northern and southern trees and animals grow 

 and live side by side. In this zone we enter 

 the true agricultural part of our country, and 

 the hardier crop plants attain their highest 

 perfection. In the Carolinian zone trees 

 adapted to a warmer climate, like the sassa- 

 fras and tulip tree, first make their appear- 

 ance, and the semi-hardy fruits, the sweet 

 potato, tobacco, and the hardier grapes reach 

 their best conditions. In the Ausiro -riparian 

 zone, the long-leaved pine, magnolia, and live 

 oak are common on the uplands, and the bald 

 cypress and cane in the swamps ; the animals 

 and birds are characteristic. This is the 

 zone of the cotton plant, sugar cane, rice, 

 pecan, and peanut, and of tender fruits. Still 

 farther south is the Tropical region, which 

 in the United States is restricted to southern 

 Florida and extreme southeast Texas, along 

 the Rio Grande and the Gulf coast. The 

 Division of Ornithology and Mammalogy is 

 engaged in tracing the courses of these re- 

 gions across the continent, and in the prepa- 

 ration of large scale maps on which their 

 boundaries are shown in different colors. 



Antillean Elevations and Depressions. 



A study by Charles Torres Simpson, on the 

 distribution of the land and fresh-water 

 mollusks of the West Indian region, touches 

 upon the evidence they afford with regard 

 to past changes of land and sea. The author 

 finds that a considerable proportion of the 

 land snail fauna of the Greater Antilles 

 seems to be ancient and to have developed 

 on the islands where it is now found. There 

 appears to be good evidence of a general ele- 

 vation of that region after most of the more 

 important groups of snails had come into 

 existence, at which time the larger islands 

 were united and a land connection existed 

 with Central America by way of Jamaica, 

 and a considerable exchange of species went 

 on between the two regions. At some time 

 during this elevation there was probably a 

 landway from Cuba across the Bahama pla- 

 teau to the Floridian area, over which cer- 

 tain groups of Antillean mollusks crossed. 



This period was followed by one of general 

 subsidence, during which Jamaica was first 

 isolated, then Cuba, and afterward Hayti and 

 Porto Rico. The connection between the 

 Antilles and the mainland was broken, and 

 the Bahama region, if it had been previously 

 elevated above the sea, was submerged ; the 

 subsidence continuing until only the summits 

 of the mountains of the Greater Antillean 

 islands remained above water. Then followed 

 another period of elevation, which has lasted, 

 no doubt, until the present time, and the large 

 areas of limestone uncovered in the Greater 

 Antilles furnished an admirable field for the 

 development of the groups of land snails that 

 survived on the summits of the islands. The 

 Bahamas have appeared above the surface of 

 the sea, either by elevation or growth, and 

 have been peopled by faunas drifted from 

 Cuba and Hayti, and a number of land and 

 fresh-water species have been colonized in 

 south Florida. The Lesser Antilles have 

 been peopled for the most part from South 

 America. 



Smoking in Mashonaland. The luxuries 

 indulged in by the Mashonas appear, accord- 

 ing to W. A, Eckenberg, of the railroad sur- 

 vey, " to be confined to tobacco not usually 

 smoked, but taken as snuff and beer manu- 

 factured from the seed of the millet. Drunk- 

 enness is an uncommon vice, except among 

 certain of the chiefs. In the coast districts 

 hemp is smoked in a hookah pipe of simple 

 construction. A long, narrow gourd forms 

 the body of the pipe. Halfway down it a 

 hole is made of a convenient size for apply- 

 ing the lips. The gourd is filled with water 

 halfway to the level of the hole. Through 

 the closed top is inserted a small hollow reed, 

 reaching nearly to the bottom of the water, 

 and protruding well beyond the upper end 

 of the gourd. To the upper end of the reed 

 is fixed the clay or stone bowl of the pipe, 

 and this is of very small size, capable of 

 holding only a sufficient quantity of hemp 

 for a few whiffs. The smoker, holding the 

 gourd upright to prevent the escape of the 

 water, applies his lips to the hole, and draws 

 the smoke to his lungs, through the water, 

 by two or three vigorous inhalations. The 

 result is made known to the whole neighbor- 

 hood by a violeut and apparently purposely 

 exaggerated coughing and spluttering ; the 



