906 



SCIENCE 



[N. S. Vol. XXXIX. No. 1016 



where the disease is present in a field the 

 greater infection occurs where the alfalfa 

 weevil is also present. This disease is so in- 

 jurious that fully 80 per cent, of the first 

 cutting may he lost on account of it. How- 

 ever, while the chief damage is usually noted 

 in the first cutting, the plants may be seriously 

 injured in the crowns and roots, thus causing 

 entire plants to be killed. 



P. J. O'Gaea 

 Laboratory op Plant Pathology, 

 American Smelting and Repining Co., 

 Salt Lake City, Utah, 

 May 16, 1914 



FURTHER NOTES ON TAMARISK 



Judging from Mr. Carleton's remarks^ and 

 the writer's experience Tamarix gallica is an- 

 other of those interesting plants that will grow 

 in very dry as well as in exceedingly wet places. 

 This species is extensively planted at Belle 

 Isle, Vermillion Parish, in the broad coastal 

 marsh of Louisiana. The soil here is always 

 saturated with water and is subject to inun- 

 dation by exceptional tides. The plant is 

 known as salt-water cedar, and its main use 

 is for firewood. Little of that commodity is 

 needed in this austral locality, and sections of 

 the limbs of Tamarix, in size from the thick- 

 ness of a finger to that of the wrist, answer 

 every purpose. The plants are pollarded and 

 closely pruned but quickly produce a new 

 crop of firewood. 



W. L. McAtee 



U. S. Department op Agriculture, 

 "Washington, D. C. 



a factor for the fourth chromosome of 

 drosophtla 

 A NEW character has recently appeared in 

 Drosophila in which the wings are " bent." 

 The factor concerned does not fall within any 

 of the three groups of linked factors so far 

 described. There are four pairs of chromo- 

 somes in Drosophila (without taking into 

 account possible complications of the XY 

 pair). The number of chromosomes now 



1 Science, N. S., XXXIX., pp. 692-694, May 

 8, 1914. 



corresponds therefore with the number of 

 independent groups of factors. The corre- 

 spondence goes even further than number, 

 however, for the sex-linked group is known to 

 be distributed with the X chromosome, and 

 all the groups correspond in their size-rela- 

 tions with the chromosomes, there being three 

 large groups and one small, just as in the case 

 of the chromosomes. The factor for " bent " 

 forms the small " group " by itself, and ac- 

 cordingly may be considered to lie in the 

 small chromosome. 



Hermann J. Muller 



DICKERSON^ ON CALIFORNIA EOCENE 



Two brief but valuable papers by Mr. 

 Dickerson call attention to the fact that the 

 apathy with which the Eocene of California 

 has been treated since Gabb's time is less on 

 account of any last word having been said 

 on the subject than the overshadowing eco- 

 nomic importance of the later Tertiary hori- 

 zons of the state. 



The use of the name Tejon to embrace all 

 the post-Martinez Eocene of the Pacific coast 

 and the recognition of the section south of 

 Mt. Diablo as a standard for this formation 

 can hardly meet with general approval. It 

 appears that this section is composed exclu- 

 sively of beds belonging to a formation 

 stratigraphically younger and separated from 

 the horizon at the type section in the Canada 

 de las Uvas near Fort Tejon by several thou- 

 sand feet of strata as well as a considerable 

 time gap. 



The writers- have shown that in Oregon 

 and Washington the Eocene may be divided 

 into three faunal divisions, the Chehalis, 

 Olequa, and Arago or lone formations. The 



1 Dickerson, Boy E., "Fauna of the Eocene at 

 Marysville Buttes, California," Bull. Dept. Geol. 

 Univ. of California, VII., p. 257-298, PI. XI.- 

 XIV., 1913; "Note on the Faunal Zones of the 

 Tejon Group," lac. eit., VIII., No. 2, p. 17-25, 

 1914. 



2 Arnold, R., and Hannibal, H., ' ' The Marine 

 Tertiary Stratigraphy of the North Pacific Coast of 

 America," Proc. Am. Phil. Soc., LII., No. 212, 

 p. 559-605, 1913. 



