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1. Na235SO4, [1-14C]glucosamine and [1-14C]acetate were used as precursors of the sulphated glycosaminoglycans to study the biochemical effect of β-aminopropionitrile in chick embryos. The incorporation of all three precursors was decreased in the treated embryos between days 7 and 10 of embryonic development. No inhibition of incorporation of these precursors occurred between days 16 and 20 of embryonic development at the dosages of β-aminopropionitrile used. 2. β-Aminopropionitrile treatment also decreased the amount of N-acetylhexosamines in the chick embryo and decreased the percentage of the hexosamine esterified by nucleotides. Respiration was decreased by homogenates prepared from treated embryos. Likewise, UDP-xylosyl- and UDP-galactosyl-transferase activities were decreased in treated embryos and cartilage from embryos and growing chicks. 3. The data suggest that β-aminopropionitrile, in addition to the known lathyrogenic activity, either is or gives rise to a potent metabolic poison that interferes with basic cellular metabolism. The results are consistent with a decreased rate of ATP generation as an explanation for the decrease in glycosaminoglycan synthesis.

Abundant microcline-perthite megacrysts mantled by plagioclase ($$An_{20}$$) occur sporadically in Precambrian granites over a wide area in northeastern Wisconsin. Earlier workers offered the novel suggestion that this rapakivi texture is a unique variety of perthite formed during brecciation of the granite. The mineralogy and chemistry of these feldspars has been reinvestigated optically and with an electron microprobe. Many of the newer observations are inconsistent with the earlier theory. The mantling is older than the brecciation and independent of it. Besides mantling, the megacrysts exhibit multiple zoning and what are regarded as resorption and synneusis textures. The chemical composition of the two feldspar phases indicates that they equilibrated under relatively uniform, subsolvus conditions. It is concluded that this rapakivi texture is a primary magmatic feature which has been considerably modified by late-stage recrystallization and exsolution. The sequence of crystallization of feldspars deduced on textural grounds is: (1) alkali feldspar, (2) alkali feldspar + oligoclase, (3) mantling of alkali feldspar by oligoclase, (4) a second stage of alkali feldspar formation, (5) further mantling by oligoclase, and (6) late-stage alkali feldspar growth, exsolution, and ordering.

Neonatally thymectomized female mice were studied and compared to appropriate controls. Neonatal thymectomy appears to decrease fertility significantly in the female C3H/HeJ mouse. However, if a thymectomized female mouse becomes pregnant, pregnancy offers significant protection against wasting disease and death. The maternal thymus appears to play no significant role in the development of the fetus as measured by gross examination and organ weights. Offspring of thymectomized females had comparable body and organ weights when compared to offspring from sham-operated females, except for the thymus gland and gastrointestinal tract. The absence of the maternal thymus gland did stimulate a significant increase in the gland weight of her offspring compared to sham-operated control female offspring. Parity, per se, in intact females also causes a significant increase in the weights of the thymus of newborn offspring.

Discusses faultlines in southern California, prediction of earthquakes, and the likelihood of a major quake in the near future.

To the Editor:—In their important article "Treatment of Pernicious Anemia by a Special Diet" (The Journal, August 14), Minot and Murphy honor me by quoting one of my articles in relation to deficiency as a cause of pernicious anemia. The authors, however, misunderstood my work and this wants rectification. Though in the article to which they refer and in other publications I defended the view that pernicious anemia must be caused by deficiency, I never thought or wrote that I thought it was caused by lack of a single known or still unknown vitamin. Pernicious anemia is a complicated symptom complex and therefore it is, in my opinion, caused by a lack of different substances in the food, which are to be found in a diet rich in complete proteins (meat, milk, yellow of eggs) and rich in the known vitamins. This led me to treat pernicious anemia with

Laron identified a group of children with severe growth failure and high levels of immunoreactive human growth hormone (IR-HGH). To investigate why these patients often have elevated HGH, we studied a 7½ year old Saudia Arabian boy with a height of 85 cm (HA 2yrs) and basal IR-HGH levels of 32 to 84 ng/ml (normal—less than 5 nanagrams per ml). Fasting blood sugars were often in the hypoglycemic range, and hyperglycemia induced by glucose infusion did not suppress his high IR-HGH. The serum IR-HGH was increased markedly by arginine infusion. High dose HGH treatment (7.5 mg q 12 hrs × 9 doses) did not modify his IR-HGH response 1 hour after arginine (increment over control was 111 and 121 ng/ml before and after treatment). Plasma sulfation factor (SF) was low and did not rise with treatment, as it does in the usual HGH deficient patient. Chronic adminsitration of HGH (2.5 mg × per week) produced a modest growth acceleration of 2.6 cm over the 5 months period compared to an expected response of 6.5 to 12 cm per year, in patients lacking HGH.These studies suggest that the persistently elevated IR-HGH is due to either a lack of SF to suppress the hypothalamic growth hormone releasing factor or that the hypothalamic HGH receptors share the same defects as those receptors responsible for the initiation of SF synthesis. Regardless of the interpretation, the IR-HGH in these patients does not appear to be under the hypothalamic control system demonstrable in normal individuals.