What are the 'Calcichordata'? and the larger question of the origin of Ghordates

Argument around the question of the validity of the 'Calcichordata' emphasizes the need for a more functional and utilitarian view of the origin of the chordates. The calcichordate question is reviewed and 'tested' in terms of our usual ideas of biological reality. The concept is rejected and the Stylophora are viewed as aberrant and still largely unknown echinoderms. Rejection of the calcichordate concept turns us once more to the question of the origin of the chordates. A number of competing hypotheses are compared: the tunicate, dipleuruloid and archicoelomate models. The conclusion is that the dipleuruloid, a simple metazoan, offers the least explanatory difficulties. Also it is concluded that discussion of such a subject as this refines and improves our thinking concerning it.     

Corsets,Culture and Contingency: Reflections on Joan Lindsay's Picnic at Hanging Rock1

This article turns an anthropological sensitivity onto a literary text from its own society. It takes Joan Lindsay's novel ‘Picnic at Hanging Rock’ and ‘reads’ it in the light of ideas prominent in recent anthropological writings (the ideas of Lévi-Strauss are particularly used): it also articulates an interpretation by using notions current in modern literary and cultural analysis. The article points out that Lindsay's text has most commonly been interpreted as being about mysterious natural forces injurious to man. Whilst the text explores the disjunction between nature and culture, the article interprets the text as exploring the nature of cultural institutions and cultural processes.     

The Cochlear Duct of Lizards and Snakes

The gross morphology of the cochlear ducts of approximatelyhalf (150) of the living genera of lizards and a third (130)of the living genera of snakes have been studied. The differencesin the structure of the cochlear duct are related to both theacoustical capacities and the taxonomic relationships of certainlizards and snakes. The cochlear duct of lizards consists offairly well joined lagenar and limbic portions. By contrast,the cochlear duct of snakes consists of a lagenar sac somewhatconstricted from the limbus. Each family of lizards has a morphologicallycharacteristic cochlear duct, but taxonomic relationships areindicated by certain anatomical similarities. The cochlear ductof snakes is more primitive than that of lizards, and, unlikelizards, does not exhibit marked specializations of its variousparts. Differences in morphology of the cochlear duct in snakesare much more related to habitat than family. The limbus andpapilla basilaris of snakes regardless of family, are most elongatedin bin rowing species, are only moderately elongated or ovoidin terrestrial species, and are small or reduced in certainarboreal and aquatic species.     

The Effect of Dissolved Oxygen Concentration on Growth and Differentiation of Carrot (Daucus carota) Tissue

For suspension cultures of carrot tissue there is a criticallevel of dissolved oxygen concentration. Below this level, dryweight increased linearly with time while cell numbers increasedexponentially, creating ‘meristematic-like’ conditionsin the culture. These conditions favoured differentiation intoplantlets by embryogenesis while conditions above the criticallevel, when both cell dry weight and cell numbers increasedexponentially, favoured plantlet differentiation by rhizogenesis.Different light treatments affected the yield of structuresformed but did not prevent oxygen from controlling the differentiationpathway.     

A prospective study of human papillomavirus infection of the cervix

In a prospective study 42 women, diagnosed as having low grade cervical intraepithelial neoplasia (CIN), made a total of 281 clinic visits over a 45 month period. At each visit, they were subjected to cytological and colposcopical examination and samples were taken for human papillomavirus (HPV) DNA hybridization studies and for the detection of non-HPV infections. HPV types 16 and/or 18 were found in 25% of all the samples tested and these virus types were detected in five of six (83%) women whose lesions progressed compared to seven of 14 (50%) of those whose lesions regressed. The presence of HPV DNA was not a good prognostic indicator of progression since half of those whose disease regressed also harboured these viruses at some time. The recording of non-HPV infections almost 10 times more often in the women whose disease regressed than in those whose disease progressed could probably be accounted for by the former having a larger number of follow-up visits. Nevertheless, the significance of non-HPV infections also remains unclear.