1921 



AMERICAN BEE JOURNAL 



481 



est in this connection to record a sim- 

 ilar case in eastern Maryland. The 

 followinK observations by Dr. Phillips 

 on the secretion of nectar by tulip- 

 tree have, I believe, never before been 

 published: "Tulip-tree g7"ows in asso- 



Kansas the good alfalfa pasturage 

 for bees is restricted to the narrow 

 stream valleys, while the uplands, no 

 natter how gi-eat their elevation, 

 yield little nectar, owing to the small 

 rainfall. A beekeeper at Oshkosh, 

 Neb., on the Platte River, writes that 

 although sweet clover and alfalfa are 

 ybundant at an altitude of nearly 

 4,000 feet, the air is so dry that little 

 nectar is secreted, and that his ex- 

 perience in beekeeping has been a 

 failure. The small amount of experi- 

 mental evidence available is not very 

 satisfactory; but, so far as it goes, it 

 points to no relation between atmos- 

 pheric pressure and nectar secretion. 

 But according to the 29-year record 

 at Clai-inda, Iowa, a low barometer 

 apparently favored honey production. 

 Any definite conclusion until more 

 data is obtained, seems, therefore, im- 



possible. It is by no means improba- 

 ble, assuming all other factors to be 

 favorable, that a slight change in air 

 pressure might start nectar secretion, 

 for example, when the cells of the 

 nectary are overfilled with water and 

 the elastic walls of the cells are under 

 great strain. 



Red Coloration and the Sug^ar Con- 

 tent of Alpine Plants 



Very conclusive evidence that 

 plants at Alpine heights produce more 

 sugar than in the lowlands is shown 

 by the great amount of red and pur- 

 ple coloration they contain. Mueller 

 ("Alpenblumen", p. 563) gives a list 

 of flowers which contain more and 

 brighter red and blue pigments than 

 the same species contain in the low- 

 lands. But the red coloration is by 

 ro means confined to the flowers; it 



Blo>soms of white sweet clover 



elation with chestnut, oak, walnut, 

 hickory, maples and beech, and some- 

 times with scrub pines. Its chief im- 

 portance as a honey plant is in Ten- 

 nessee, Kentucky and the Carolinas, 

 and the Ohio Valley. In Virginia and 

 Maryland it is perhaps less abundant, 

 although near Washington, above the 

 fall line, it is sufficiently abundant to 

 give a regular honey crop. We never 

 secured a crop from this species when 

 our apiai-y was below the fall line, in 

 the city, or at Arlington, Va., or Col- 

 lege Park, Md." 



The "fall line" is the line separating 

 the Coastal Plain from the Piedmont 

 Plateau, or the line where the tide- 

 water rivers cease to be navigable. In 

 Virginia this ascent ranges from 100 

 to 200 feet, but in eastern Maryland 

 it is probably less. It is noteworthy 

 that in the higher part of the city of 

 War.hington tulip-tree yields well, but 

 not in the lower part. 



The obvious explanation of the se- 

 cretion of nectar by alfalfa and 

 tulip-tree at higher altitudes, in the 

 localities mentioned, would seem to 

 be the decrease in atmospheric pres- 

 sure. At Alpine heights the evapora- 

 tion of water vapor Ijy leaves is hast- 

 ened by the thinness of the air. But 

 it may be urged with much force that 

 a rise of only one or two hundred 

 feet would make little difference in 

 air pressure. As a matter of fact 100 

 feet would cause a decrease in air 

 pressure of only a little more than 

 eight-tenths of an ounce per square 

 inch. Moreover, under favorable con- 

 ditions, the secretion of nectar by 

 alfalfa is largely independent of air 

 pressure, since in Imperial Valley, 

 California, 200 feet below sea level, 

 it yields immense crops of honey. In 



Blossoms of the barberry {Berbcris ziilgaiis). A Northern shrub which blooms earlier in 

 Arctic regions than further south 



