. Genetics in relation to agriculture. Livestock; Heredity; Variation (Biology); Plant breeding. MITTATIONS 273 rably associated with variegation. Correns lias pointed out that variegated Mirabilis plants cannot be considered mosaics of green and 'chlorina' types due to heterozygosis, since they do not segregate into chlorina and green, but into variegated and green. The same reasoning applies to variegation in the color of maize ears. Varicgated-eared plants do not throw reds and whites, but reds and variegates. The conclusion seems in-esistible that self-color occurring as a somatic variatio
. Genetics in relation to agriculture. Livestock; Heredity; Variation (Biology); Plant breeding. MITTATIONS 273 rably associated with variegation. Correns lias pointed out that variegated Mirabilis plants cannot be considered mosaics of green and 'chlorina' types due to heterozygosis, since they do not segregate into chlorina and green, but into variegated and green. The same reasoning applies to variegation in the color of maize ears. Varicgated-eared plants do not throw reds and whites, but reds and variegates. The conclusion seems in-esistible that self-color occurring as a somatic variation is due to the change of a Mendelian factor for variegation into a factor for self-color. If this be granted, the behavior of these variations in later generations is a mere matter of simple ]\Iendelian ; If bud sports are caused by mutations and if most bud sports involve a change from the dominant to the recessive condition of a certain factor, it follows that the change in chemical constitution must affect both of the. Fig. 112.^Bud sport and chimera in an ear of corn. This ear appeared in a field of white dent corn. The apparently white kernels, occupying about 3^ of the surface, wero actually variegated, being marked with "fine red lines, or streaks, radiating from the caps down the sides of the ; (After Hartley.) duplex factors present in the somatic cell in order that the recessive character may appear. To those who think of mutations as fortuitous events, this may seem an obstacle to the conception that bud sports are the result of factor mutations. But from the point of view that factor mutations are caused, probably by some specific internal condition, it would seem most natural for the cause to have the same effect on both factors. Obviously this conception assumes that in such cases the specific cause, whatever it is, has the same potentiality in all parts of the nucleo- plasm, and there is no a priori logical objection to such an
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