Formation of the photosynthetic apparatus in dark-grown 2-day-old beán (Phaseolus vulgaris L.) leaves was studied. The photosystem 2 (PS 2) reaction centres started íunctioning 1 h after the beginning of irradiation. Electron transport between the two photosystems started after 4 h of irradiation. The PS 2 units were able to transfer the excitation energy to each other after 10 h of greening. The photosynthetic activity appeared a long time before the typical 77 K fluorescence bands of green leaves appeared.
This study analyses marital fertility in the 19th century in the parish of Rožmberk nad Vltavou, which is located in Southern Bohemia. In the 19th century this region was stagnating economically. Its lack of development was reflected in demographic changes. The natality and fertility rates remained almost unchanged even in the 19th century. Changes that did occur were caused by the rising age of marriage more than by an effort to regulate the number of children bom. Throughout the period under observation families tended to have around 4-5 children on average. During the century the number of pre-marital conceptions increased (around 20-25). Despite the increase in the number of pre-marital conceptions, the majority of children tended to be bom roughly 8-12 months after marriage. Other children were bom at intervals of 2 to 2.5 years, and women tended to have their last child around the age of 40. Women’s fertility was especially high at the start of the marriage, and then it gradually declined after the age of 30. However, fertility remained at the same level throughout the century and was only slightly lower than in the 18th century. Couples in the Rožmberk parish showed no tendency to limit the number of children bom; a more important role was played by the age of the spouses at the time of marriage, which influenced the number of fertile years a woman experienced while married. A fundamental change was the reduction in the mortality rate of women as a result of childbirth and postnatal complications. On the other hand, infant and child mortality in the 19th century continued to be relatively high: by the age of five just over one-quarter of all children bom had died (26.2 %) and the rate of stillbirths hovered around 2%. The minor changes that did occur in the 19th century among the Rožmberk population were not pronounced enough for us to be able to speak about this society’s transition to new demographic structures.