Darwin and Modern Science [192]
purpose of causing pain or for doing an injury to its possessor." ("Origin of Species" (1st edition) 1859, page 201.)
The study of adaptation always had for Darwin, as it has for many, a peculiar charm. His words, written Nov. 28, 1880, to Sir W. Thiselton- Dyer, are by no means inapplicable to-day: "Many of the Germans are very contemptuous about making out use of organs; but they may sneer the souls out of their bodies, and I for one shall think it the most interesting part of natural history." ("More Letters" II. page 428.)
PROTECTIVE AND AGGRESSIVE RESEMBLANCE: PROCRYPTIC AND ANTICRYPTIC COLOURING.
Colouring for the purpose of concealment is sometimes included under the head Mimicry, a classification adopted by H.W. Bates in his classical paper. Such an arrangement is inconvenient, and I have followed Wallace in keeping the two categories distinct.
The visible colours of animals are far more commonly adapted for Protective Resemblance than for any other purpose. The concealment of animals by their colours, shapes and attitudes, must have been well known from the period at which human beings first began to take an intelligent interest in Nature. An interesting early record is that of Samuel Felton, who (Dec. 2, 1763) figured and gave some account of an Acridian (Phyllotettix) from Jamaica. Of this insect he says "THE THORAX is like a leaf that is raised perpendicularly from the body." ("Phil. Trans. Roy. Soc." Vol. LIV. Tab. VI. page 55.)
Both Protective and Aggressive Resemblances were appreciated and clearly explained by Erasmus Darwin in 1794: "The colours of many animals seem adapted to their purposes of concealing themselves either to avoid danger, or to spring upon their prey." ("Zoonomia", Vol. I. page 509, London, 1794.)
Protective Resemblance of a very marked and beautiful kind is found in certain plants, inhabitants of desert areas. Examples observed by Burchell almost exactly a hundred years ago have already been mentioned. In addition to the resemblance to stones Burchell observed, although he did not publish the fact, a South African plant concealed by its likeness to the dung of birds. (Sir William Thiselton-Dyer has suggested the same method of concealment ("Annals of Botany", Vol. XX. page 123). Referring to Anacampseros papyracea, figured on plate IX., the author says of its adaptive resemblance: "At the risk of suggesting one perhaps somewhat far- fetched, I must confess that the aspect of the plant always calls to my mind the dejecta of some bird, and the more so owing to the whitening of the branches towards the tips" (loc. cit. page 126). The student of insects, who is so familiar with this very form of protective resemblance in larvae, and even perfect insects, will not be inclined to consider the suggestion far-fetched.) The observation is recorded in one of the manuscript journals kept by the great explorer during his journey. I owe the opportunity of studying it to the kindness of Mr Francis A. Burchell of the Rhodes University College, Grahamstown. The following account is given under the date July 5, 1812, when Burchell was at the Makkwarin River, about half-way between the Kuruman River and Litakun the old capital of the Bachapins (Bechuanas): "I found a curious little Crassula (not in flower) so snow white, that I should never has (have) distinguished it from the white limestones...It was an inch high and a little branchy,...and was at first mistaken for the dung of birds of the passerine order. I have often had occasion to remark that in stony place(s) there grow many small succulent plants and abound insects (chiefly Grylli) which have exactly the same colour as the ground and must for ever escape observation unless a person sit on the ground and observe very attentively."
The cryptic resemblances of animals impressed Darwin and Wallace in very different degrees, probably in part due to the fact that Wallace's tropical experiences were so largely derived from the insect world, in part to the importance assigned by Darwin to Sexual Selection "a
The study of adaptation always had for Darwin, as it has for many, a peculiar charm. His words, written Nov. 28, 1880, to Sir W. Thiselton- Dyer, are by no means inapplicable to-day: "Many of the Germans are very contemptuous about making out use of organs; but they may sneer the souls out of their bodies, and I for one shall think it the most interesting part of natural history." ("More Letters" II. page 428.)
PROTECTIVE AND AGGRESSIVE RESEMBLANCE: PROCRYPTIC AND ANTICRYPTIC COLOURING.
Colouring for the purpose of concealment is sometimes included under the head Mimicry, a classification adopted by H.W. Bates in his classical paper. Such an arrangement is inconvenient, and I have followed Wallace in keeping the two categories distinct.
The visible colours of animals are far more commonly adapted for Protective Resemblance than for any other purpose. The concealment of animals by their colours, shapes and attitudes, must have been well known from the period at which human beings first began to take an intelligent interest in Nature. An interesting early record is that of Samuel Felton, who (Dec. 2, 1763) figured and gave some account of an Acridian (Phyllotettix) from Jamaica. Of this insect he says "THE THORAX is like a leaf that is raised perpendicularly from the body." ("Phil. Trans. Roy. Soc." Vol. LIV. Tab. VI. page 55.)
Both Protective and Aggressive Resemblances were appreciated and clearly explained by Erasmus Darwin in 1794: "The colours of many animals seem adapted to their purposes of concealing themselves either to avoid danger, or to spring upon their prey." ("Zoonomia", Vol. I. page 509, London, 1794.)
Protective Resemblance of a very marked and beautiful kind is found in certain plants, inhabitants of desert areas. Examples observed by Burchell almost exactly a hundred years ago have already been mentioned. In addition to the resemblance to stones Burchell observed, although he did not publish the fact, a South African plant concealed by its likeness to the dung of birds. (Sir William Thiselton-Dyer has suggested the same method of concealment ("Annals of Botany", Vol. XX. page 123). Referring to Anacampseros papyracea, figured on plate IX., the author says of its adaptive resemblance: "At the risk of suggesting one perhaps somewhat far- fetched, I must confess that the aspect of the plant always calls to my mind the dejecta of some bird, and the more so owing to the whitening of the branches towards the tips" (loc. cit. page 126). The student of insects, who is so familiar with this very form of protective resemblance in larvae, and even perfect insects, will not be inclined to consider the suggestion far-fetched.) The observation is recorded in one of the manuscript journals kept by the great explorer during his journey. I owe the opportunity of studying it to the kindness of Mr Francis A. Burchell of the Rhodes University College, Grahamstown. The following account is given under the date July 5, 1812, when Burchell was at the Makkwarin River, about half-way between the Kuruman River and Litakun the old capital of the Bachapins (Bechuanas): "I found a curious little Crassula (not in flower) so snow white, that I should never has (have) distinguished it from the white limestones...It was an inch high and a little branchy,...and was at first mistaken for the dung of birds of the passerine order. I have often had occasion to remark that in stony place(s) there grow many small succulent plants and abound insects (chiefly Grylli) which have exactly the same colour as the ground and must for ever escape observation unless a person sit on the ground and observe very attentively."
The cryptic resemblances of animals impressed Darwin and Wallace in very different degrees, probably in part due to the fact that Wallace's tropical experiences were so largely derived from the insect world, in part to the importance assigned by Darwin to Sexual Selection "a