Recent Evolution in Milk Secretion of Guernsey Cattle.

Solar Vortices," Contributions from the Mount Wilson Observatory, No. 109; Astrophysical Journal, 43, 347 (1916). The electromagnetic theory of solar vortices was developed by Professor Stormer merely as a working hypothesis and not as an expression of his opinion regarding the nature of these phenomena. The legend of figure 9 in Professor St6rmer's article is incorrect: the words "clockwise" and "counter-clockwise" should be transposed. 2 This sign is not known. If positive instead of negative, the polarity of the spots in the cases given will be reversed. Near the end of his paper Stormer concludes that galvanic currents are more probable than convection currents of charged particles. I Hale, Ellerman, Nicholson and Joy, "The Magnetic Polarity of Sun-spots," Contributions from the Mount Wilson Observatory, No. 165; Astrophysical Journal, 49, 165 (1919). 4 Hale, "The Law of Sun-spot Polarity," these PROCEEDINGS, 10, 53 (1924). ^ Hale and Luckey, "Some Vortex Experiments Bearing on the Nature of Sun-spots and Flocculi," these PROCEEDINGS, 1, 385 (1915).