Evolution of flower specialization in bees, the concepts of poly-, oligo- andmonolecty are reviewed. About 60 species recorded in the area of Finland and Sweden are regarded as oligolectic. The proportions of oligoleges among all pollen-collecting bee species are about 30 percent in alarge area of central and Northern Europe. The proportion is about 15 percent in the northern boreal area of Finland and Sweden, where the percentage of polylectic bumblebees is much greater than in more southern areas. Of the solitary bee species recorded in Finland and Sweden, 25 arc regarded as narrow oligoleges, of which 6 species collect pollen from Campanula and 5 from Salix. Eusocial Bombus consobrinus is regarded as a facultative narrow oligolege of Aconitum septentrionale and, apparently, this bee species is the only oligolege in northern Europe, whose distribution completely covers that of the pollen plant. The distribution limits of some narrow oligoleges (e.9. Eucera longicornis and Andrena hattorfiana) approximately follow certain frequencies of their principal pollen plants (lathyrus pratensis and Knautia, respectively). Of the oligolectic bee species in Finland, 32 occur on the lists of threatened species of England, southwestern Germany or Poland. Records of E. longicornis and A. hattorfiana from various periods are given as examples of the decline of oligolectic bees in Finland during recent decades.

Enzyme gene variability in fifteen hymenopteran species, mainly bees, has been studied. The species were Apis mellifera L., six Bombus species, Macropis labiata F., Colletes succincta L., three Andrena species, Vespula vulgaris L., Mimesa equestris F. and Pontania vesicator Bremi. The hymenopteran species reproduce by arrhenotokous parthenogenesis so that the males are haploid and the females are diploid. The present results, as also the earlier studies, show that the number of polymorphic loci and the amount of heterozygosity are smaller in haplodiploid than in diploid insect populations. This is in accordance with theoretical expectations, as both deterministic selection models and the neutral hypothesis predict that genic variability is reduced in haplodiploid populations. The average heterozygosity per locus is lower in eusocial than in solitary species. The difference is not statistically significant, but it may indicate that either small effective population sizes or stable conditions in the nests of eusocial species affect genic variation.

Spatial and temporal distribution of the species in the Bombus lucorum species complex, B. lucorum (L.), B. cryptarum (Fabricius) and B. magnus Vogt, were studied in Finland. Morphological distinction between the species is not as clear as in Central Europe, but B. lucorum can be distinguished from the other two with the help of enzyme genetic markers. B. lucorum is the most common of the three species in most of Finland, and B. cryptarum is abundant in the southwestern coastal area and in northern Lapland. B. magnus was only rarely found among the spring queens in southwestern Finland, and its range possibly restricts to southern and central parts of Finland. A comparison of the chemical composition of the male labial glands and enzyme genotypes shows that males produce species-specific marking pheromones.

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Distribution and phenology of ten Ancistrocerus and eight Symmorphus species in Finland and the northwestern U.S.S.R. are presented on the basis of 8495 specimens from public and private collections. A. nigricornis, S. fuscipes and S. murarius are shown to have retreated during the last few decades from a large area of their former range in Finland. The proportions of A. antilope, A. parietum, S. allobrogus and S. crassicornis have decreased, while the proportion of A. parietinus has considerably increased in the area after the year 1970. Decrease of dead deciduous trees is one possible reason. A. parietum and A. trifasciatus are possibly bivoltine in southern Finland.

The transfer of diazepam through the placenta during labour was studied by the gas chromatographic method developed by us using a Ni63‐electron capture detector. 10 mg of diazepam was given intramuscularly to 37 patients during the first stage of labour 5‐401 min before delivery, after which blood samples were immediately collected from the umbilical cord and the maternal vein. Diazepam was found in all the plasma samples with very great individual variation in the concentrations. In one particular case, in which the delivery took place 5 minutes after the diazepam injection, the corresponding diazepam concentrations in the cord plasma and in the maternal plasma were 506 ng/ml and 504 ng/ml. In 31 cord plasma samples collected 26‐401 min after the diazepam injection the mean diazepam concentration was 70 ng/ml, and in the maternal plasma was 38 ng/ml. The average foetal/maternal concentration ratio during the same time period was 2.0 and in the whole series 1.8. Neither the diazepam concentrations in the cord plasma nor the foetal/maternal ratios of the concentrations had any significant influence on the Apgar scores of the newborns. The cause of the diazepam accumulation in the foetal circulation is unclear. The better binding of diazepam with the foetal plasma proteins is discussed. The importance of individual drug doses to parturients according to their weight is emphasized.

Very significantly lower concentrations of diazepam at 15 minutes and 1 hour after 10 mg intravenous diazepam injection were found in chronic alcoholic patients in comparison to healthy controls. Compared to 13 healthy controls a more rapid elimination of diazepam from the plasma of 14 chronic alcoholic patients during their alcohol-free period was observed. The alcoholics had a smaller concentration of the diazepam main metabolite, N-demethyldiazepam, and at 3 hours this difference was significant. The concentrations of free plasma oxazepam as a metabolite of diazepam, were not observed after a single dose of diazepam either in the alcoholics or in volunteers. A more rapid elimination of diazepam after 5 mg/kg intraperitoneally in the plasma of rats pretreated with ethyl alcohol (15 % in drinking water for 3 weeks) was found than in the control rats. Pretreatment of rats with ethyl alcohol increased significantly the concentration of the hydroxylated metabolite, free oxazepam, in the plasma, but not of the demethylated metabolite, N-demethyldiazepam.

The pharmacokinetics of nitrazepam in saliva and serum was studied in 12 healthy volunteers after a single administration of a 5 mg nitrazepam tablet. The binding of nitrazepam to plasma proteins was determined 4 hours after the administration by ultracentrifugation. The analysis of nitrazepam concentrations was performed by 63Ni‐EC‐GLC. The pharmacokinetic parameters were evaluated manually or by AUTOAN‐program in serum, and manually in saliva. The concentrations of nitrazepam in serum and saliva correlated significantly (r=0.472, P<0.001, n=97). The ratio saliva: serum was, however, time dependent. The protein free fraction in serum was significantly higher (P<0.01) than the salivary concentration at the same time (4 hours after administration). The peak concentrations in serum and saliva were 40.7 and 1.9 ng/ml (P<0.001) and the times to reach the peak maximum 2.4 and 2.5 hours, respectively (difference not significant). The mean half‐life of nitrazepam in serum was 30.5 hrs and in saliva 39.9 hrs, the difference being significant at P<0.05. The distribution phase parameters, poorly described before, were calculated. The clinical value of nitrazepam analysis in saliva seems to be negligible.