Apell 5, 1907] 



SCIENCE 



541 



Pine-barrens extend as far west as Texas, 

 and there ouglit to be some species of pine- 

 barren plants confined to Louisiana and Texas, 

 but too little is known of the flora of those 

 parts as yet. 



Plants of muddy swamps seem from all ac- 

 counts to be most numerous in the Mississippi 

 embayment of the coastal plain, from about 

 the mouth of the Ohio River southward. 

 Characteristic species of this region, most of 

 them woody plants, are: 



Taxodium distichum, Echirwdorus radicans, 

 Arundinaria macrosperma, HymenocalKs occi- 

 dentalism Leitneria Floridana, Micoria Pecan, 

 H. aquaticaj Quercus Michauxii, Q. lyrata, 

 Planera aquatica, Celiis occidentalis, Brun- 

 nichia cirrhosa, Platarms occidentalis, Cra- 

 taegus viridis, C. apiifolia, Amorpha fruticosa. 

 Ilex decidua, Acer saccharinum idasycarpurn) , 

 Berchetnia scandens, Nyssa uniflora, Bumelia 

 lycioides, Adelia acuminata, Trachelospermum 

 difforme, Asclepias perennis, Oonolohus Icevis, 

 Yincetoxicum gonocarpos, Bignonia cruciglia, 

 Tecoma radicans, Conoclinium coelestinum, 

 Mihania scandens, Eupatorium serotinum. 



Host of these are not wholly confined to the 

 coastal plain, but they are more common there 

 than elsewhere, and few if any of them ever 

 ascend more than 1,000 feet above sea-level. 

 Going eastward in the coastal plain they be- 

 come perceptibly scarcer. There are fewer of 

 them in Georgia than in Alabama, still fewer 

 in the Carolinas, and only about half of them 

 reach Virginia, though there is nothing in the 

 climate to hinder them, as far as known. 



In contrast to these five or six evident cen- 

 ters a few of the regions with poorer flora may 

 be mentioned. 



The coastal plain of Delaware, Maryland and 

 Virginia seems to lack many of the species 

 common to New Jersey and the southern pine- 

 barrens, though some of them will probably 

 be reported when those parts are better ex- 

 plored. South Carolina too seems to be a 

 rather uninteresting state floristically, and 

 there are perhaps no good species confined to 

 it. The upper fourth of the coastal plain of 

 Georgia (i. e., that part outside of the pine- 

 barrens) has quite a diversified topography 

 and vegetation, but practically all the plants 



growing there range either northward to tha 

 mountains or coastward to the pine-barrens. 



A part of the Cretaceous and Eocene regions 

 of the coastal plain from western Alabama 

 through northern Mississippi and West Ten- 

 nessee to Kentucky is remarkable for the 

 paucity of its flora. It is entirely outside of 

 the pine-barrens, and nearly all of its species 

 seem to be common and widely distributed. 

 The same remarks will probably apply to the 

 coastal plain of Arkansas. 



The ultimate reason why so many species 

 are found in some parts of the coastal plain 

 and so few in others is still obscure, and pern 

 haps each center will require a different ex- 

 planation. But the importance of locating 

 these centers is obvious; for any one who 

 wishes merely to collect as many species as 

 possible will save time by confining his opera- 

 tions to the vicinity of known centers, and the 

 possibilities of discovering new species are 

 greater there than in the poorer regions. 

 When the species belonging to each center are 

 more accurately listed it may then be possible 

 to discover their significance. 



C. Stuart Gager, 



Secretary 



DISCUSSION AND CORRESPONDENCE 



INHERITANCE OF THE BELT m HAMPSHIRE SWINE 



The Hampshires are a breed of black and • 

 white hogs, the white being confined to a belt 

 around the body at the shoulders, sometimes 

 occurring also on the hind feet and the tip of 

 the tail. The breed has recently risen to 

 prominence in the middle west. Its origin is 

 somewhat obscure. Hogs of this peculiar 

 coloring are seen occasionally throughout the 

 south, north to the Ohio River, and even be- 

 yond. The white belt in hogs the breeding of 

 which is left to chance behaves in a very 

 erratic manner, usually occurring in only a 

 small proportion of any herd. Even amongst 

 registered Hampshires about 10 per cent, of 

 the progeny is without the belt. Breeders have 

 endeavored to eliminate the ' blacks,' i. e., hogs 

 lacking the belt, but are not yet able to avoid 

 them. The writer recently undertook to col- 

 lect data from breeders with a view to an- 

 alyzing the belt character, and thus learning 



