Several flowers bloom about the same time as the spring migration, like columbine (Aquilegia canadensis), clove currant (Ribes aureum var. villosum), and red buckeye (Aesculus pavia). These ...

YESTERDAY I had an opportunity of convincing myself by direct observation that the change of colour in the flowers of Pulmonaria officinalis is of the same significance as in Ribes aureum and ...