Summary

Cites cases of leguminous plants whose cleistogamic flowers produce more seed than perfect flowers. [See Forms of flowers, p. 326.]

Summary

Informs CD that in his experience with peas he has never found the seed to deteriorate.

Summary

Podostemaceae flowering under water.

Summary

His observations on Subularia: has never seen it in flower in the air.

Summary

Informs CD that the "dishonest mollusks" were collected in May 1855 in Porto Santo. Describes some Madeira species. Though believing in "species" more and more, these may be "mere insular modifications".

Summary

Has done New Zealand flora calculations. Results support CD’s theory of necessity of crossing. Trees tend to have separate sexes.

Summary

Agassiz has informed him that the mice and rats of Mammoth Cave are American in type.

Alludes to CD’s doubt of the principle that "progress of life on the globe is parallel with the development in different tribes". Outlines his own ideas on the "unfolding of the type-idea" and its "parallelism with the law of development in the embryo".

Summary

Notes on the comparative rarity of intermediate forms between species, and the varying relationships those forms may have to one or both species between which they are intermediate.

Summary

His experience confirms CD’s view that some species and even some genera of Brachiopoda are consistently more variable than others, and that such variable forms are variable in all localities and at all periods. Similarly a species that shows a lack of variability does so at all points in time and space. Discusses the causes of variability. [See Natural selection, p. 106.]