220 



SCIENCE 



[N. S. Vol. XLII. No. 1076 



has not heretofore been described, so far as the 

 writer is able to determine. It occurs chiefly 

 in the middle and western portions of the 

 United States and appears to be increasing 

 from year to year in some localities. By actual 

 count in a large number of commercial fields 

 it affects from ten to twenty per cent, of the 

 stand and thereby threatens to become a limit- 

 ing factor in sugar-beet culture in some areas. 

 It makes its appearance about mid-summer and 

 is easily recognized by the following char- 

 acteristic. 



The leaves affected are mottled yellow and 

 green. The spots are not always sharply de- 

 fined, but usually shade into each other, giving 

 the affected leaves a yellowish appearance. 

 Frequently only a part of the leaves on the 

 same beet are affected, at least during the 

 early stages of the disease. The remaining 

 leaves seem to be perfectly normal in color 

 and growth. The leaves showing the disease 

 symptoms vary in number from one to many 

 on the same plant. They have shortened 

 petioles, usually dwarfed and frequently 

 thickened blades. The affected leaves, if nu- 

 merous, generally occupy one side only of the 

 beet crown and extend from the outer whorl 

 on one side of the crown to or past the center. 

 The normal leaves occupying the opposite side 

 of the crown give to the beet top a one-sided 

 appearance. Occasionally all the leaves of a 

 mosaic beet show the characteristic symptoms 

 mentioned above. This is generally the case 

 at or near harvest time. The shortened pet- 

 ioles give the leaves a tufted appearance, as 

 in the case of curly-top. 



The root is dwarfed and often hairy, thereby 

 further resembling curly-top. The affected 

 beets usually persist until harvest time, but 

 those, attacked early in the season are too small 

 to be of any commercial value. It is evident 

 that the assimilative functions of the beet are 

 seriously impaired, but the real cause of the 

 disease is not yet known. As indicated above, 

 there are several particulars in which the two 

 diseases, curly-top and sugar-beet mosaic, are 

 similar, but even though they are both fre- 

 quently found in the same field, they are easily 

 distinguished the one from the other. The 



writer has suggested sugar-beet mosaic as a 

 tentative name for this disease. It is hoped 

 that the investigations now under way will 

 establish the real cause of the disease, enable 

 us to find a practical remedy and suggest a 

 more satisfactory name. C. O. Townsend 



DELPHINUS AND PHOC-^NA IN THE DELAWARE 



Occasionally cetaceans enter the Delaware 

 and wander up into fresh water, thoiigh appar- 

 ently not above tidal influence. On January 

 21, 1915, a dolphin (Delphinus ddphis) was 

 found at Eiverton, New Jersey. It was about 

 six feet in length. I examined it several days 

 later, when the skeleton was shipped to Phila- 

 delphia, for the miiseum of the Academy. 

 Though the dolphin has been taken in New 

 York Harbor, and once at Ocean City in New 

 Jersey in 1894, no other records of its occur- 

 rence in New Jersey limits have ever been 

 given. 



The harbor porpoise (Phoccsna phoccena) has 

 been credited with ascending various of the 

 larger rivers of New Jersey, as well as the 

 Delaware, though no actual identified speci- 

 mens appear to have been noted. I only know 

 of one, which was washed ashore above Bristol, 

 Pennsylvania, during the summer of 1904. It 

 had been floating about with the tides for 

 some time previously, having been first located 

 at Bordentown, New Jersey. It was a rather 

 small specimen, and not preserved. 



Henry W. Fowler 



Academy of Natural Sciences of 

 Philadelphia 



SCIENTIFIC BOOKS 

 Ouidehook of the Western United States: 

 Part A, Northern Pacific Eoute, with a side 

 trip to Yellowstone Park ; Part B, Overland 

 Route, with a side trip to Yellowstone Park; 

 Part C, Santa Fe Eoute, with a side trip to 

 Grand Canyon of the Colorado; Part B, 

 Shasta Eoute and Coast Line ; Bulletins 611, 

 612, 613, 614, respectively. United States 

 Geological Survey. Washington, 1915. 

 The second of these is at hand and presum- 

 ably is representative of the four in general 



