Summary

Germination of Megarrhiza.

Summary

Describes the flower and mode of action of a particular orchid.

Has been examining Spiranthes and is experimenting to see whether insects are necessary for its fertilisation.

It seems that Oncidium is designed so as not to be fertilised.

Summary

Thanks for the letter from Volney Rattan [see 12553].

Discusses protective adaptation of seedlings from frost.

Summary

Thanks for AG’s reviews [of Movement in plants] in the Journal and Nation [Am. J. Sci. 3d ser. 21 (1881): 245–9 and Nation 32 (1881): 17–18], especially for AG’s comment about Frank Darwin.

Summary

Asks AG to forward [unspecified] enclosure to Chauncey Wright.

Summary

Is collecting facts on variation; questions AG on the alpine flora of the U. S.

Sends a list of plants from AG’s Manual of botany [1848] and asks him to append the ranges of the species.

Summary

Suggests AG append ranges to the species in the new edition of his Manual.

Is interested in comparing the flora of U. S. with that of Britain and wishes to know the proportions to the whole of the great leading families and the numbers of species within genera. Would welcome information on which species AG considers to be "close" in the U. S.

Summary

Geographical distribution. "Close" species. Hopes AG will write an essay on species.

Summary

"Close" species in large and small genera.

Alphonse de Candolle on geographical distribution [Géographie botanique raisonnée (1855)].

Species variability.

Summary

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.

Summary

Asks whether Allegheny Mountains are sufficiently continuous so that plants could travel from north to south along them.

Hopes AG’s work on geographical distribution is progressing, as he has questions on plants common to Europe which do not range up to Arctic.

Are intermediate varieties less numerous in individuals than the varieties they connect?

Summary

Rarity of intermediate varieties.

Variability of introduced plants.

Ranges of plants common to Europe and U. S.

Summary

Thanks AG for the first part of his "Statistics [of the flora of the northern U. S.", Am. J. Sci. 2d ser. 22 (1856): 204–32; 2d ser. 23 (1857): 62–84, 369–403]

and for information on social and varying plants.

Would like to know number of genera of introduced plants in U. S.

Is surprised at some affinities of northern U. S. flora and asks for any climatic explanations.

Asks what proportion of genera common to U. S. and Europe are mundane.

Is glad AG will work out the northern ranges of the European species and the ranges of species with regard to size of genera.

Summary

Variability of naturalised plants.

Distribution of Arctic/alpine plant species.

Limits to the northern range of plants.

Summary

Thanks AG for 2d part of "Statistics [of the flora of the northern U. S.", Am. J. Sci. 2d ser. 22 (1856): 204–32; 2d ser. 23 (1857): 62–84, 369–403].

Is glad AG concludes species of large genera are wide-ranging, but is "riled" that he thinks the line of connection of alpine plants is through Greenland. Mentions comparisons of ranges worth investigating.

Believes trees show a tendency toward separation of the sexes and wonders if U. S. species bear this out. Asks which genera are protean in U. S.

Summary

Urges AG to generalise from his observations on the flora of the northern U. S.

Expected to find separation of sexes in trees because he believes all living beings require an occasional cross, and none is perpetually self-fertilising. The multitude of flowers of a tree would be an obstacle to cross-fertilisation unless the sexes tended to be separate.

The Leguminosae are CD’s greatest opposers; he cannot find that garden varieties ever cross. Could AG inquire of intelligent nurserymen on the subject?

Thanks AG for information on protean genera; much wants to know whether their great variability is due to their conditions of existence or is innate in them at all times and places.

Summary

Describes problems of classifying species in highly variable genera. Lists highly variable genera. Comments on the list of Asa Gray. Says species may be made to appear more or less variable according to whether a genus is divided into few or many species.

Summary

Thanks for new part of "Statistics".

Interested in disjoined species; do they tend to belong to large or small genera, and are they generally members of small families?

Is glad AG will tackle introduced plants; has noticed that the proportion of a particular family to the whole flora tends to be similar in introduced and indigenous plants.

Summary

Thanks for AG’s remarks on disjoined species. CD’s notions are based on belief that disjoined species have suffered much extinction, which is the common cause of small genera and disjoined ranges.

Discusses out-crossing in plants.

Has failed to meet with a detailed account of regular and normal impregnation in the bud. Podostemon, Subularia, and underwater Leguminosae are the strongest cases against him.

Summary

Believes species have arisen, like domestic varieties, with much extinction, and that there are no such things as independently created species. Explains why he believes species of the same genus generally have a common or continuous area; they are actual lineal descendants.

Discusses fertilisation in the bud and the insect pollination of papilionaceous flowers. His theory explains why, despite the risk of injury, cross-fertilisation is usual in the animal and vegetable kingdoms, even in hermaphrodites.