SUMMARY The geographical features, in particular the western escarpment, and the climate and vegetation of western Angola combine to divide the area into three avifaunal zones. An unusual relationship exists between some related forms of different zones. This is illustrated by two groups of examples in which the characters of the forms are summarised, their distribution is shown on maps, and an attempt is made to interpret in evolutionary terms the picture presented. Endemic or near‐endemic forms of the Escarpment Zone are listed with some notes on their affinities with other species. The botanical history of the area is discussed in relation to the conclusions reached on the evolution of the birds. The Escarpment Zone of Angola has been of considerable importance in the evolution of species in western Africa, south of the Equator.

The average increase of soybean [Glycine max (L.) Merr.] grain yield per year is not enough to meet the estimated need by 2050. Contributing factors may include narrowing genetic diversity in cultivated soybean germplasm arising from direct selection for grain yield and insufficient knowledge of the genetic influences on physiological traits associated with grain yield. Canopy development plays a critical role in the light intercepted by soybean crops throughout the growing season. Rapid canopy closure facilitates complete light interception and optimizes growth dynamics, ultimately increasing biomass accumulation and grain yield. This study sought to use ground-based digital imagery as a phenotyping tool for quantitative characterization of seasonal canopy coverage and light interception in the genetically diverse Soybean Nested Association Mapping (SoyNAM) population. We took weekly measurements of canopy coverage from early vegetative to mid-reproductive growth for 5,600 recombinant inbred lines during the 2013 and 2014 seasons. An asymptotic logistic growth curve fit to the coverage data allowed us to estimate daily changes in canopy coverage in the intervals between the sampling dates, enabling calculation of canopy dynamic parameters. These parameters included average canopy coverage, cumulative intercepted photosynthetically active radiation for the total sampling period, vegetative growth period, reproductive growth period, and the number of days required to reach 30, 50, and 70% canopy coverage. Variance component estimation showed that genetic differences among families significantly influenced variation in phenotypic expression for all canopy parameters. The narrow-sense heritabilities for all canopy parameters were high (h 2 = .81-.90), suggesting opportunities for genetic gains in canopy development through selection of superior genotypes.

SUMMARY 1. The relationship between the Black and Grey Tits of Africa is discussed briefly. 2. Variable characters in the Black Tit are listed, on which five forms can be distinguished. 3. The characters, ranges and ecology of the five forms are set out, with some discussion on atypical populations within the forms, and on the variable population of central and southeastern Uganda. 4. It is concluded that speciation is taking place in many populations of Black Tits and that this presents considerable difficulties in assessing the relationship between forms. 5. Reasons are given for considering P. n. niger and P. n. carpi as specifically distinct from other forms. The question of whether guineensis should be considered specifically distinct from P. I. leucomelas and P. I. insignis is left open until more is known of their field characters in Uganda and Abyssinia. Similarly purpurascens is regarded as a variable race until more field study has been done.