Sexes of algae.
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Sexes of algae.
Continues earlier discussion, admitting his opinions have been modified. Still regards natural selection as one agent of several. States areas of disagreement.
Thanks CD for his patience and good-nature; does not want a controversial correspondence but wishes to reply to matters in CD’s letter, and does.
Is pleased that CD has [Roland] Trimen to collect specimens of Cape orchids. Suggests directions for securing dry specimens of what he draws.
Identifies Disa barbata and D. Cornuta of the Ophridiae.
Sends dandelion [enclosed] with peculiar form of achene; suggests this solitary "sport" must have arisen by sudden jump from normal type.
The plants from the Cape did not show climbing habit in native country; WHH believes it a consequence of their being grown under disadvantages of climate.
Identifies South African species of plants that are normally non-climbers in the wild but climb freely when grown from seed at Glasnevin. Thinks there is probably a gradation in the wild between climbing and non-climbing varieties related to the degree of exposure each particular plant faces.
Has examined his specimens discussed in his previous note and adds further observations.
Descriptions of the algae specimens found on the Beagle voyage.
W. J. Hooker thinks Harvey will be willing to give information on reproduction of higher marine plants.
Thanks for information, which is just the amount he wanted.
Will not go to the BAAS meeting in Dublin: the frightful voyage deters him.
Replies to WHH’s criticisms of the Origin. Is disappointed that WHH does not understand what CD means by natural selection. CD has said "ad nauseam" that selection can do nothing without previous variability. Natural selection accumulates successive variations in any profitable direction. If CD had to rewrite his book he would use "natural preservation" rather than selection. Defends his necessarily conjectural illustrations. Agrees with what WHH says on the antiquity of the world, but it makes no impression on him. Considers the difficulty of the first modification of the first protozoan. Emphasises that there is nothing in his theory "necessitating in each case progression of acquisition", nor is it the case that "a low form would never conquer a high" in the struggle for life. Attempts to explain what he means by a "dominant" group; dominance is always relative, and he does not believe any one group could be predominant. He has no objections to "sudden jumps"; they would aid him in some cases, but he has found no evidence to make him believe in them and a good deal pointing the other way.