On the origin of neoblasts in freshwater planarians (Turbellaria)

Experiments on 1) regeneration of the cave-adapted planarian, Sphalloplana zeschi, 2) induction of sexuality in an asexual strain of Dugesia japonica japonica by feeding, and 3) culture of dissociated planarian cells, show that neoblasts originate from intestinal cells, i.e. phagocytic cells and granular clubs.     

棉蚜性蚜的研究

调查了棉蚜性蚜的种群动态,对性母、性雄、性雌内外生殖系统进行了研究、观察、解剖与描述,并对性雌产卵习性、产卵量以及交配习性进行了研究。讨论了性蚜产生的生态条件及性雄、性雌性别决定先后次序和来源问题。     

Darwin was a teleologist

It is often claimed that one of Darwin's chief accomplishments was to provide biology with a non-teleological explanation of adaptation. A number of Darwin's closest associates, however, and Darwin himself, did not see it that way. In order to assess whether Darwin's version of evolutionary theory does or does not employ teleological explanation, two of his botanical studies are examined. The result of this examination is that Darwin sees selection explanations of adaptations as teleological explanations. The confusion in the nineteenth century about Darwin's attitude to teleology is argued to be a result of Darwin's teleological explanations not conforming to either of the dominant philosophical justifications of teleology at that time. Darwin's explanatory practices conform well, however, to recent defenses of the teleological character of selection explanations.I would like to thank John Beatty, David Hull and one of this journal's readers for constructive comments on an earlier draft of this paper.     

Biosystematic investigations on the lady fern(Athyrium filix-femina)

In EuropeAthyrium filix-femina has a constant chromosome number (2n = 80) and is sexual. The normal type of reproduction is intergametophytic crossing. In the gametophyte phase there is a hormone system which induces dark germination of spores and antheridium formation. Sporophytes originating from single prothalli show that a genetic load is present in all population examined. It appears not to be a simple allelic load but a complicated balanced system. Morphological variability can be interpreted as the expression of the genetic heterogeneity of populations. There are no crossing barriers, not even between insular populations hundreds of kilometers apart.     

The Life Cycle of Cryptochlora perforans (Chlorarachniophyta)

Observations on the behaviour of different life cycle stages, gamete fusions, and measurements of nuclear DNA contents in Cryptochlora perforans resulted in a first concept concerning life histories in Chlorarachniophyta: the life cycle of Cr. perforans is diplohaplontic (gamete fusion with karyogamy - mitosis - meiosis - mitosis). In the haploid as well as in the diploid life cycle phases amoeboid and coccoid stages occur. The isomorphic gametes are modified amoebae frequently without filopodia. Only haploid flagellate stages are known representing mito- or meiozoospores. Diploid coccoid stages have a granular cytoplasmic structure and may be somewhat larger than haploid ones. Nevertheless, positive identification of haploid (gametophytic) and diploid (sporophytic) stages is only possible on the basis of nuclear DNA contents.     

Magico‐spiritual power,female sexuality and ritual sex in Muslim Java: Unveiling the kesekten of magical women

This article argues that in practice, concepts of magico‐spiritual power (Javanese: kesekten; Indonesian: kesaktian) are linked with sexuality, particularly female sexuality, in some segments of contemporary Central and East Javanese Muslim society. Few scholars have turned attention to the interconnectedness of these seemingly contradictory topics. Feminist studies tend to focus on the ways in which women locate themselves within and critique Sharia‐based discursive and social orders, without considering the roles that magico‐spiritual power and associated practices play in these Islamic systems or in Islam in a more general sense. Similarly, male scholarship that considers the cultural relevance of Islam and magic rarely refers to gendered and sexual dimensions as praxis from a feminist perspective. By drawing on examples of ‘magical women’ including the Javanese spirit queen of the southern ocean Gusti Kanjeng Ratu Kidul, the historical Hindu figure Ken Dedes, and contemporary ritual sex practices at a Muslim saint's grave, we show how women, female spiritual beings and female sexuality, and sexuality in general, can be considered sources of magico‐spiritual power in Muslim Java. Our arguments conclude that in Javanese Islam, transgression of Sharia sexual norms can be both a sign and a source of magico‐spiritual power.     

Genetic variation in organisms with sexual and asexual reproduction

The genetic variation in a partially asexual organism is investigated by two models suited for different time scales. Only selectively neutral variation is considered. Model 1 shows, by the use of a coalescence argument, that three sexually derived individuals per generation are sufficient to give a population the same pattern of allelic variation as found in fully sexually reproducing organisms. With less than one sexual event every third generation, the characteristic pattern expected for asexual organisms appear, with strong allelic divergence between the gene copies in individuals. At intermediary levels of sexuality, a complex situation reigns. The pair-wise allelic divergence under partial sexuality exceeds, however, always the corresponding value under full sexuality. These results apply to large populations with stable reproductive systems. In a more general framework, Model 2 shows that a small number of sexual individuals per generation is sufficient to make an apparently asexual population highly genotypically variable. The time scale in terms of generations needed to produce this effect is given by the population size and the inverse of the rate of sexuality.     

"Showing roughness in a beautiful way": talk about love, coercion, and rape in South African youth sexual culture

Sexual violence within as well as outside sexual relationships has far-reaching public health and human rights implications and is a continuing focus of popular debate, media coverage, and research in postapartheid South Africa. Partly because it has been shown to affect individual vulnerability to HIV/AIDS, sexual violence has in recent years become framed as a global public health issue. International research efforts to document the scale of this personally and politically sensitive problem can encounter conceptual, definitional, and methodological difficulties that anthropology is well placed to assist in alleviating. This article offers an ethnographic exploration of the spectrum of practices relating to sexual coercion and rape among young people in a township in the former Transkei region of South Africa. Contextualizing meanings of sexual coercion within local youth sexual culture, the article considers two emic categories associated with sex that is "forced": ukulala ngekani: "to sleep with by force" or ukunyanzela: "to force," both usually used to describe episodes occurring within sexual partnerships; and ukudlwengula, used to describe rape by a nonpartner or stranger. The article discusses the semantic content of and differences between these two key categories, demonstrating that encounters described as "forced sex" encompass not only various forms of sexual coercion but also, particularly in the narratives of young men, instances of more consensual sex. Of importance, in turn, in defining an act as "rape" rather than as "forced sex" are the character of the relationship between the two parties and interlinked ideas relating to exchange and sexual entitlement, love, and the importance of "intention," violation, and "deserving" victimhood.     

Genital cutting and western discourses on sexuality

This article explores dominant discourses surrounding male and female genital cutting. Over a similar period of time, these genital operations have separately been subjected to scrutiny and criticism. However, although critiques of female circumcision have been widely taken up, general public opinion toward male circumcision remains indifferent. This difference cannot merely be explained by the natural attributes and effects of these practices. Rather, attitudes toward genital cutting reflect historically and culturally specific understandings of the human body. In particular, I suggest that certain problematic understandings of male and female sexuality are deeply implicated in the dominant Western discourses on genital surgery.     

Sexuality issues in the movement to abolish female genital cutting in Sudan

Ethnographic research in seven rural Sudanese communities in 2004 demonstrates the deep association between infibulation and expectations for successful male sexual response, reinforced by aesthetic values about the preferred body form for females. In contrast, women conceive of the uninfibulated body as lacking in both propriety and beauty, as well as making a woman less able to please a husband sexually. Female sexual response has only recently begun to be discussed in the context of change efforts to end female genital cutting.