474 



SCIENCE 



[N. S. Vol. XXVII. No. 690 



occurs in great abundance on the dry flinty 

 hills of the Ozark region, where it is as- 

 sociated with black-jack and post oaks, and 

 with white hickory. Both of these hill 

 hickories are known locally as " bull hickory," 

 there being very little to distinguish them 

 except the foliage. The glahra form is the 

 commonest tree in the hills, where it is usually 

 rather small — occasionally twelve inches in 

 diameter and fifty feet high — with very thick, 

 rough bark separating into small squares like 

 the proverbial alligator hide; a rather deep 

 cylindrical crown of small branches, and 

 small, lanceolate, shiny leaflets. 



The reproduction of this "alligator hick- 

 ory " is very good, and is especially abundant 

 on hills which are burned over every year, 

 these being sometimes covered with nearly 

 pure thickets of hickory seedlings and seed- 

 ling-sprouts. These are injured less by the 

 burnings and recover more readily than the 

 small oaks, afterward, and hence are the sole 

 survivors where fires occur frequently. Ex- 

 amination of the seedlings, however, shows 

 them to be very old, and proves beyond a doubt 

 that their development is very much retarded 

 by the exposure. 



The drought-resistance of this hickory is 

 even more remarkable than its fire-resisting 

 powers. After a midsummer drought of eight 

 weeks, both the black-jack and post oaks were 

 in very bad condition, a large proportion of 

 the foliage having turned brown, or the trees 

 killed outright. The hickory, on the other 

 hand, showed only a slight deadening of the 

 leaves in the tops of a few trees. The ex- 

 planation of this superior drought-resistance 

 is undoubtedly to be found in the small, thick- 

 skinned leaves which characterize the alligator 

 hickory, and which are typical of xerophytic 

 plants. The tendency to form a long, strong 

 tap-root, which all hickories exhibit when 

 growing in well-drained soil, is certainly a 

 very potent factor here. 



Such characters as these recommend the 

 alligator hickory for planting in the prairie 

 states, and in dry situations in more humid 

 regions. The high technical value of the 

 wood should in part offset the very slow 

 growth of the tree. It is not to be expected 



that the hickory will attain to merchantable 

 size in less than seventy to one hundred years. 

 In that period it should produce a considerable 

 quantity of spoke and handle stock of the very 

 highest quality, if grown on soils of reasonable 

 strength. The planting of hickory on light 

 soils can not be recommended under any cir- 

 cumstances. 



C. G. Bates 

 U. S. Forest Service, 

 Washington, D. C. 



CURRENT NOTES ON METEOROLOGY AND 

 CLIMATOLOGY 



kassner's meteorological globes 

 Professor C. Kassner, of the Prussian 

 Meteorological Institute and also of the 

 Technische Hochschule in Berlin, has pre- 

 pared two " meteorological globes " which will 

 be of great help to teachers of geography in 

 general, and especially to those who lay much 

 emphasis on meteorology and climatology. 

 These globes (diameter 34 centimeters) show, 

 for January and for July, the temperature, 

 pressure and winds of the world. The tem- 

 perature is shown by isotherms for every 2°, 

 and in places for every 4° C. ; the isotherm 

 of 0° C. is drawn heavier than the others; 

 those parts of the globe which are warmer than 

 0° are colored red, and those colder than 0° 

 are colored blue. Different shades of red and 

 blue are used for different degrees of heat and 

 cold. Isobars are drawn in blue, the isobar of 

 Y60 mm. being heavy; those below 760 mm. 

 are broken lines; those above, solid lines. 

 Winds are indicated in the usual way by 

 arrows. The principal meteorological stations 

 the world over are shown; the observatories, 

 and the central stations of the various meteor- 

 ological services are appropriately emphasized 

 by special symbols. 



By an ingenious device the globes can be 

 turned over, while still remaining on their 

 wooden stands, so that the southern latitudes 

 may be readily seen. These globes will help 

 greatly in giving a clearer conception of the 

 actual distribution of temperatures, pressures 

 and winds than can be gained from a study 

 of the ordinary meteorological charts. While 

 the globes are too small for exhibition' 



