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A process of nucleolar reorganization apparently identical to that encountered in intestinal epithelial cells (Adamstone and Taylor, '72) develops in kidney cells of aging rats. The polymorphic nucleoli of young tubule cells soon change to amphinucloeli and, while terminal nucleolar reorganization is delayed in cells of collecting tubules, in the nephrons nucleoli soon begin to undergo terminal reorganization becoming bipartite structures with separate plasmosomes and karyosomes. This suggests disruption of the DNA-dependent RNA protein transcription system and failure to maintain the flow of messenger RNA into the cytoplasm. Old cells are not discarded immediately from the kidney tubules and they retain much rough endoplasmic reticulum, numerous ribosomes and polysomes and large plasmosomes. Thus a high RNA concentration is known to develop in old kidney tissue while protein synthesis is also known to be low (Kanungo et al., '70; Buetow and Ghandi, '73). Nucleolar counts show gradual increase in bipartite nucleoli at the expense of amphinucleoli and in the senescent kidney bipartite nucleoli predominate. It is suggested that nucleolar reorganization, with final separation of plasmosomes and karyosomes, includes the process of nucleolar segregation and is triggered by some innate nucleolar mechanism in response to encoded genetic information stored in the nucleolus during nucleogenesis. At this time both DNA and RNA are incorporated into the developing nucleolus. It is also to be noted that two shifts in nucleolar dominance occur with advancing age. These may be fundamental to the process of aging and to the onset of senescence. Furthermore, the changes in dominant nucleolar types are the direct result of the process of nucleolar reorganization.

An early study of vitamin E deficiency in the chick embryo' showed that death of the embryo was usually accompanied by hemorrhage and that the site of bleeding presented a characteristic histological picture (FIGURE 7 ) .A similar condition was later shown to occur in supposedly normal chick embryos.2 Since then, Mason3 has shown that hemorrhage frequently occurs in vitamin E-deficient rat fetuses, although no histologic reaction was reported at the site of hemorrhage. I t has also been found by Adamstone that hemorrhage may occur in pig embryos, the condition having been first observed in routine laboratory class study of 10 mm. pig embryos (FIGURE 6). In this case, moreover, the histological picture is almost identical to that seen in the chick (cf. FIGURES 6 and 7 ) , and, frequently, clusters of degenerating pycnotic cells are found in blood vessels throughout the body (FIGURE S), just as also occurs in the chick. It was recognized, of course, that the condition observed in the pig might not be related to vitamin E deficiency, but examination of about 600 embryos revealed hemorrhage in approximately 10 per cent of the cases. Hence, hemorrhage is undoubtedly an important cause of fetal death. Therefore, an investigation of the possibility that vitamin E deficiency is involved seems justified. Plan of the ExperimentA group of nine gilts (7 Duroc Jersey and 2 Poland China) were selected for the test and were divided into 3 lots. These gilts averaged 70 pounds in weight at the beginning of the experiment and had been raised in continuous confinement on concrete floors. For 75 days prior to the beginning of the experiment they had been fed a wellbalanced ration. During the entire vitamin E test, the gilts were also confined on concrete floors and were hand-fed twice daily. (b) Experimental Rations. Since large quantities of food are necessary for such an experiment, a natural ration was used rather than a more costly, purified diet. The ingredients, composition, and vitamin content of the basal ration used in the experiment are given in TABLE 1. This was fed to the gilts in Lot 1. The ration contained more than the nutrient allowances recommended by the National Research Council,$ and all rations used were adequate except for vitamin E. The tocopherol content of this ration was of the order of 1.4 mg. per pound of food. Thus, since an average of 5.7 pounds of food was consumed by each pig per day, the total daily intake of vitamin E was quite low. I n Lot 2, the basal ration was supplemented with 10 per cent rancid lard to ensure further depletion of vitamin E. In Lot 3, the basal ration (a) Aiiimals and Management.

Red males over a period of approximately 2 years.Mating experiments showed that after 1 year on the E-free diet all of the males were capable of fertilizing ova, hut that after 2 years some of the males were sterile.Sperm smears showed that shortly after the beginning of the experiment, many of the mature sDermatozoa exhibited a n abnormal condition of the nuclear material of the head. ~ ~~~.~~~

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