5.9 Pollen, spores and parasite eggs
Five pollen samples have been analysed, three from cesspit 2 and two from cesspit 4, in each case derived from the bottom layers of the fills (table 2). The results are discussed in general, in view of the similarity of the pollen spectra of all samples.
The most frequent pollen type is that of cereals (Cerealia), of which only rye (Secale cereale) could be identified to species level. The abundance of cereal pollen is most likely linked with the consumption of grain products, since a high amount of pollen stays attached to the grains after the plant has flowered. The same must be the case with arable weeds like corncockle (Agrostemma githago), chamomile type (Anthemis type), cornflower (Centaurea cyanus), white lace flower (Orlaya grandiflora) and corn poppy type (Papaver rhoeas type), of which seeds must have been brought in to the flour mill and bakery together with grain. Other food plants represented in the pollen spectra are parsnip (Pastinaca sativa), pea (Pisum sativum) and grape (Vitis vinifera). The latter pollen could have ended up in the cesspits because of the consumption of fresh grapes or raisins, although drinking wine might also be an explanation (Rösch 2005). Kitchen herbs are represented by chervil (Anthriscus cerefolium), borage (Borago officinalis) and coriander (Coriandrum sativum).
Table 2 Results of the analysis of pollen, spores and non-pollen palynomorphs (specimen counts).
An alternative explanation for (at least) part of the pollen of cereals and their associated weeds might be the use of straw or hay for stuffing mattresses or covering the floor. Yet another possible source for part of the pollen may have been the consumption of honey. Typical honey plants, largely depending on bees for pollination, are trefoil type (Lotus type), white clover type (Trifolium repens type) and red clover type (Trifolium pratense type) (Sawyer 1988). Many others of the entomophilous pollen types may have arrived at the site in the same way (Deforce in press). Honey, which often contains extremely high amounts of pollen, was commonly used as sweetener in the late medieval kitchen and was a much cheaper alternative to pure sugar (Dalby 2000, Küster 2000). The pollen of common heather (Calluna vulgaris), with remarkable high values in cesspit 4, will either relate to the peat mentioned earlier, to honey, or to both. Spores of peat moss (Sphagnum sp.) do point to the presence of peat (Deforce et al. 2007). A coenobium (colony structure) of Pediastrum kawraiskyi, a green alga from oligotrophic aquatic biotopes, corroborates this interpretation.
Finally, the pollen samples also contained the eggs of intestinal parasites, i.e. Ascaris and Trichuris. These species are found in almost all cesspits from this period and must have been very common parasites of people and their animals.