A significant part of the literature concerned with the effects of alcohol on the esophagus represents clinical impressions, guilt by association, and epidemiologic observations rather than experimentation. With regard to epidemiologic data, a number of reports suggest that the chronic use of alcohol in significant amounts increases the incidence of cancer of all membranes from mouth through gullet. With regard to the latter, Tuyns (1970) cites a number of studies, including that by Wynder (1961), which demonstrate an increased incidence of esophageal cancer among heavy whiskey drinkers and littler or no increase in incidence for beer or wine drinkers. Of interest is the observation that cancer of the esophagus has a more significant correlation with chronic alcoholism than with cirrhosis.

Summary

Using the approach of Mahalanobis it was desclosed that workers ofMelipona quadrifasciata are, as far as the external morphology is concerned, closer to males than to queens of this species. A preliminary interpretation of this is given based in a slight modification of theBritten andDavidson hypothesis (batteries of genes) applied to the sex determination system of these bees. There are two sets of sex genes: one set that acts in the embryo and determines ovary or testis and another that acts in the prepupal stage determining the transformation of the imaginal discs and tegument in adult female or adult male structures. A preliminary hypothesis for gene regulation is proposed for both sets. The mode of action of the second set implies that a substance produced by food above a given limit acts on the integrator genesx^a andx^b (with two alleles each) and these put a receptor gene (R^xa+x^b) into action that by its turn, put into action the gene (or genes) for femaleness;Melipona workers are females inside (have ovaries) but are almost males in the outside, tegument, eyes, wings). The place of action of the juvenile hormone in this battery has not yet been experimentally determined, but this working hypothesis put it provisorily in the beginning of the battery.

Résumé

La fourmiCataglyphis bicolor utilise pour se diriger des repères topographiques et des repères célestes: soleil et plans de polarisation de la lumière de la voûte du ciel.

Cette espèce a été observée pendant l'éclipse totale de soleil du 30 juin 1973.

Tant que l'éclipse est partielle, les ouvrières déplacées expérimentalement prennent la direction de leur nid avec la même précision que les jours normaux. Quand le soleil est totalement occulté, elles restent immobiles.

Plusieurs hypothèses sont envisagées pour expliquer cette immobilité: photocinèse, réaction à une modification brutale de l'environment, impossibilité de détecter les plans de polarisation à cause du faible éclairement de la voûte céleste.

Zusammenfassung

Es wurde das Phänomen von Paarungsplätzen beiApis mellifica beschrieben. Diese befinden sich Jahr für Jahr an derselben. Lokalität und werden bei bestimmter Witterung und Tageszeit von ♂ ♂ aus vorwiegend 2–4 km Entfernung beflogen. Der Einfluß der Paarungsbiologie auf die Genetik wurde erwähnt.