The purpose of the present article is to show that the Newman-Janis and Newman et al algorithm used to derive the Kerr and Kerr-Newman metrics respectively, automatically leads to the extension of the initial non negative polar radial coordinate r to a cartesian coordinate r running from −∞ to +∞, thus introducing in a natural way the region −∞ < r < 0 in the above spacetimes. Using Boyer-Lindquist and ellipsoidal coordinates, we discuss some geometrical aspects of the positive and negative regions of r , like horizons, ergosurfaces, and foliation structures.

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Rick, Charles M. (U. California, Davis.), Anson E. Thompson, and Oscar Brauer. Genetics and development of an unstable chlorophyll deficiency in Lycopersicon esculentum. Amer. Jour. Bot. 46(1) : 1‐11. Illus. 1959.—A single gene gh determines a condition of variable chlorophyll deficiency in the tomato. Two independent mutations have been recorded at this locus, and both mutants exhibit the same phenotype. Linkage tests ascertained that the locus of gh lies between hl and j in group V. Graft and inoculation experiments prove that the gh phenotype is not caused by a virus. The mutant seedlings have cotyledons that can be identified by their partial chlorophyll deficiency. First true leaves may rarely have normal morphology and pigmentation; in most seedlings they show a mosaic of normal and chlorotic tissue. With subsequent growth, the plant rapidly reaches a condition of complete chlorophyll deficiency. Two constant levels of deficiency have been observed: a common white phase with very little or no chlorophyll and an infrequent yellow phase with about 5% of the normal chlorophyll content present in irregularly distributed chloroplasts. In both phases leaf lamina structure is drastically modified; petioles, stems, flowers, and fruits are much less affected. Sporadic islands of normal green coloration appear in the otherwise stable white or yellow phase. The degree of chlorophyll development is subject to great environmental modification but no evidence was obtained for genetic control in addition to the determination by gh. Depending upon environment, most gh seedlings perish before fruiting, but those with sufficient chlorophyll flower and set fruits with seeds after self‐or cross‐pollination. Most gh fruits remain white until mature, when the normal yellow epidermal pigment appears, the interior remaining white; occasional streaks or patches of chlorophyll that develop on immature fruits turn reddish at maturity. Seeds from such sectors, like all other seeds harvested from selfed gh plants, give rise only to gh progeny, thereby rendering improbable a mutational basis for the sporadic reversions to green. Applications of gh to further genetic and physiological studies are discussed.