Suggests affinities of the U. S. flora that he considers would be worth investigating. Wants to know the ranges of species in large and small genera.

Questions AG on naturalised plants; whether any are social in U. S. which are not so elsewhere and how variable they are compared with indigenous species. Would like to know of any differences in the variability of species at different points of their ranges and also the physical states of plants at the extremes of their ranges.

Proportion of molluscan species to genera in various periods. The difficulty of determining species increases with the number of species per genus. Identifying species within a genus is most difficult in that period in which the genus shows its greatest development.

No summary available.