On top of the chart below are the two McLaren brothers, Peter and John. The horizontal rows are generations and vertical lines run from parents to children. Not all children are shown, only those of current interest.
Everyone on the chart is a McLaren, so the double lines represent cousin marriages (see the discussion of consanquinity).
Second generation James and Margaret had eight children; Senator Peter was the second. Senator Peter was a lumberman, well known and highly respected.
Third generation David was both first and second cousin of Senator Peter, as well as a valued employee in his lumber business. David and Margaret had ten children. They are the paternal grandparents of my Lanark cousin, David James.
The vertical column on the right, from second generation John, is my direct line.