Tetraplold alfalfa (Medicago sativa L.) germplasm, in which two‐thirds of the plants are capable of regeneration from callus tissue in culture, has been developed by recurrent selection. It descends from one ‘DuPuits’ and four ‘Saranac’ clones which regenerated in the cycle 0 population. Frequency of regeneration was 12% in cycle 0, about 50% in cycle 1, and 67% in cycle 2. Seed produced by hand‐intercrossing 75 plants regenerated from cycle 2 has been termed ‘Regen‐S’ (Regen for regeneration; S for Saranac). It is purple‐flowered and phenotypically similar to Saranac. One‐gram lots of Regen‐S seed are presently available for distribution, and larger amounts are expected to be available in late 1975. A yellow‐flowered regenerator ‘Regen‐Y,’ is now being bred from selections out of ‘Rhizoma,’ ‘Rambler,’ and ‘Drylander.’ Small amounts of Regen‐Y seed are also presently available, thus providing a contrasting qualitative genetic marker stock.

Thirteen dams, twelve deflectors, and several covers were constructed in a 450‐yard section of Hayes Brook, Prince Edward Island, to create suitable hiding places for brook trout, Salvelinus fontinalis (Mitchill). In the following year the standing crop of fingerlings (age 0) was above average. The numbers of age I and older trout were approximately doubled. The alterations had no noticeable effect on the growth of trout.

Estimated standing crops of eels in eight Maritime lakes treated with fish poisons varied from 0 to 70.8 pounds per acre. Smaller standing crops were associated with greater distances of lakes from the sea, and with obstructions to ascending elvers. Few eels were found in small spring-fed streams. The eel is prominent in Maritime lakes, but frequently is not more successful than other fish considered inimical to game species. Seaward migrations of eels may represent major losses of organic matter to lakes.Scales appear on young eels at lengths from 16 to 20 centimetres, probably in their third or fourth year of age. Nine year-classes were found among eels with scales in each of three limnetic populations. Eels with three and four annual rings on the scales were dominant in the runs from lakes.Runs of eels from lakes occurred in April and May, and again, in larger numbers, from late August through November. These movements were at night, and usually coincident with rising water during and immediately following heavy rains. Silvering, an index of maturity, was manifest among only a portion of the largest of these eels. Fall runs of large eels from salt water into streams have been noted. Upstream movements of elvers are most prominent in May and June, although they attempted to bypass a barrier in the outlet of one lake throughout the summer.

Young plants of five Nicotiana tabacum L. genotypes were examined for activity of nicotine biosynthetic enzymes. Genotypes near isogenic except at two loci each with two alleles controlling nicotine level were used in a comparison of the four homozygous allelic combinations producing high, high intermediate, low intermediate, and low nicotine levels in a 'Burley 21" background. Putrescine N-methyltransferase (EC 2.1.1.53) and quinolinic acid phosphoribosyltransferase (EC 2.4.2.19) activities in root tissue of these four genotypes were proportional to leaf nicotine level, whereas N-methylputrescine oxidase activity in root tissue differed in proportion and ranking. Quinolinic acid phosphoribosyltransferase activities in leaf tissue were lower than in roots, but no differences were found among the four genotypes. The homozygous recessive alleles at either locus affect levels of all three enzyme activities examined in roots. Each locus seems to be involved in regulation of nicotine metabolism, but whether directly as a regulatory locus or indirectly through the metabolic product of a structural locus is not known.No difference was observed between enzymic oxidation of putrescine and N-methylputrescine by leaf and root extracts of Burley 21 (a high nicotine, low nornicotine genotype) and a high nornicotine cultivar, "Robinson Medium Broadleaf." Putrescine was utilized as a substrate to a greater extent than N-methylputrescine by leaf extracts compared with root extracts of both cultivars. It was concluded that genetic differences in levels of nicotine and nornicotine were not due to differences in enzymic oxidation of these two precursors during alkaloid biosynthesis.Nicotine is the predominant alkaloid in commercial tobacco cultivars, where it is found in concentrations of 2 to 5% of dry weight. Nicotine level as influenced by cultural practices of nitrogen fertilization, plant decapitation, water regime, and axillary bud control has been reviewed recently (2). Low total alkaloid levels are associated with homozygous recessive alleles at both the A and B genetic loci, and intermediate alkaloid levels are found when the homozygous recessive alleles are present at only one of the two loci (I 1).Nicotine, composed of single pyridine and N-methylpyrrolidine rings linked together, is synthesized primarily in the root (1,5). Support for the role of ornithine decarboxylase putrescine Nmethyltransferase (EC 2.1