July 24, 1908] 



SCIENCE 



127 



OBSERVATIONS ON MEDICAGO LUPULINA L. 



Owing to the occasional adulteration of 

 alfalfa seed with, yellow trefoil, Medicagt 

 lupulina, this plant is of considerable interest 

 to alfalfa growers in the eastern states. It is 

 encouraging to note that such adulteration is 

 less common than formerly. Of 491 samples 

 of alfalfa seed examined by the writer at the 

 New York Experiment Station during the 

 past eighteen months, only seven showed evi- 

 dence of adulteration with yellow trefoil. 



In botanical works Medicago lupulina is 

 sometimes described as an annual and some- 

 times as " annual or biennial." Careful ob- 

 servation has shown that in alfalfa fields in 

 New York it is regularly a biennial. Even 

 when the seed is sown in spring only occa- 

 sional plants blossom and seed the first year. 

 The great majority do not bloom until the 

 second year in the latter part of May, shortly 

 before the first cutting of alfalfa. At this 

 time the plants are very conspicuous because 

 of their yellow blossoms; but they do not re- 

 appear in subsequent cuttings of the alfalfa. 



That the plants actually do live over winter 

 is proved by the results of the following 

 experiment: On March 29, 190Y, nine plants 

 suspected of being M. lupulina were trans- 

 planted into the station greenhouse. Six of 

 these were taken from an alfalfa field and 

 three from a lawn on the station grounds. 

 They all blossomed and proved to be as sus- 

 pected. 



Except when the two plants are in bloom, 

 M. lupulina so closely resembles alfalfa, M. 

 sativa, that the two species are distinguished 

 with difficulty. This is especially true in the 

 early stages of growth. The writer has sought 

 unsuccessfully for morphological or anatom- 

 ical characters by means of which the two 

 species may be separated with ease and cer- 

 tainty. In early spring the most reliable 

 characters by which the two species may be 

 separated are, (1) the habit of growth of the 

 crown and (2) the character of the root sys- 

 tem. The crown of M. lupulina is spreading, 

 very similar to that of red clover, and the 

 stems are procumbent; while the crown of 

 alfalfa is upright in habit. The root systems 

 ofPer a more striking difference. Alfalfa has 



a large tap-root with very few side roots. M. 

 lupulina has a small tap-root nearly concealed 

 in a mass of fibrous side roots. 



In conclusion, it may be of interest to note 

 the finding of a M. lupulina seedling having 

 three cotyledons. G. T. French 



New Yoek Expebiment Station, 

 ■ Geneva, New Yobk 



SOCIETIES AND ACADEMIES 



THE GEOLOGICAL SOCIBTT OF WASHINGTON 



At the 207th meeting of the society, on May 

 27, Mr. P. E. Matthes discussed informally 

 " Refusion of Cinders by Camp Fires on San 

 Francisco Mountains, Arizona." Mr. L. D. Burl- 

 ing also discussed briefly " Colored Photography 

 in Geology." 



Regular Program 

 The Coalinga, California, Oil Field: Mr. Ralph 



Arnold and Mr. Robeet Anderson. 



The Coalinga District is situated on the eastern 

 flank of the Diablo Range, along the border of 

 the central valley of California. This flank of 

 the range is formed of an eastward dipping mono- 

 cline that exposes the Franciscan {probably 

 Jurassic) in the axis of the range and above this 

 about 26,000 feet of strata representing a consid- 

 erable portion of the time up to the middle 

 Pleistocene. There are at least 12,000 feet of 

 Cretaceous, including lower and upper Cretaceous, 

 with a probable unconformity between, and 14,000 

 feet of Tertiary and Quaternary beds composing 

 six mutually unconformable formations. These 

 belong to the Eocene, lower Miocene, upper Jlio- 

 eene, Pliocene and lower Pleistocene. The young- 

 est formation that has undergone folding com- 

 prises a thickness of at least 2,500 feet of un- 

 consolidated coarse and fine sediments belong- 

 ing to the Pliocene and lower Pleistocene, and 

 has been correlated with the Paso Robles forma- 

 tion of the Salinas Valley. It is of freshwater 

 origin at the base and in part marine above, but 

 is thought to have originated in large measure 

 subaerially as a filling in the Great Valley of 

 California. Great orogenic movements took place 

 in the Pleistocene and in places lifted the deposits 

 forming the floor of the central valley into steeply 

 dipping folds. Tliese folds are topographic as 

 well as structural arches and afford a rare in- 

 stance of the preservation of the original domes 

 due to warping of the surface. 



The petroleum occurs in beds and lenses of 

 sand and gravel in the Eocene, lower Miocene 



