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 c...
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 c...
All these facts prove that the velocity of development of animal life in Arctic regions,
where the temperature is near the freezing point of water, must be from two to three times smaller than in regions where the temperature of the ocean is about 10 deg C. and from four to nine times smaller than in seas the temperature of which is about 20 deg C. It is, therefore, exactly the reverse of what we should expect when authors state that the density of organisms at or near the surface of the ocean in polar regions is greater than in more temperate regions. The writer believes that th...
All these facts prove that the velocity of development of animal life in Arctic regions,
where the temperature is near the freezing point of water, must be from two to three times smaller than in regions where the temperature of the ocean is about 10 deg C. and from four to nine times smaller than in seas the temperature of which is about 20 deg C. It is, therefore, exactly the reverse of what we should expect when authors state that the density of organisms at or near the surface of the ocean in polar regions is greater than in more temperate regions. The writer believes that th...
We must look at the problem in its simplest form; we find it in every case where a new race differs essentially
the original type in a single character only; for example, in the colour of the flowers or in the petalody of the stamens (doubling of flowers). In this connection we must keep in view the fact that every visible character in a plant is the resultant of the cooperation of specific structure, with its various potentialities, and the influence of the environment. We know, that in a pure species all characters vary, that a blue-flowering Campanula or a red Sempervivum can be converted by experim...
We must look at the problem in its simplest form; we find it in every case where a new race differs essentially
the original type in a single character only; for example, in the colour of the flowers or in the petalody of the stamens (doubling of flowers). In this connection we must keep in view the fact that every visible character in a plant is the resultant of the cooperation of specific structure, with its various potentialities, and the influence of the environment. We know, that in a pure species all characters vary, that a blue-flowering Campanula or a red Sempervivum can be converted by experim...
Exner calls attention to the fact that it is in this direction especially, that the ``dark perceptions'' play a great
A great part of our intelligence depends on the ability of these `dark perceptions' to rise without requiring further attention, into the field of consciousness. There are people, e. g., who recognize birds in their flight without knowing clearly what the characteristic flight for any definite bird may be. Others, still more intelligent, know at what intervals the flyers beat their wings, for they can imitate them with their hands. And when the intelligence is still greater, it makes pos...
Exner calls attention to the fact that it is in this direction especially, that the ``dark perceptions'' play a great
A great part of our intelligence depends on the ability of these `dark perceptions' to rise without requiring further attention, into the field of consciousness. There are people, e. g., who recognize birds in their flight without knowing clearly what the characteristic flight for any definite bird may be. Others, still more intelligent, know at what intervals the flyers beat their wings, for they can imitate them with their hands. And when the intelligence is still greater, it makes pos...
The speed of apperception has been subjected to measurement by Auerbach, Kries, Baxt, von Tigerstedt and Bergqvist, Stern
The results show 0.015 to 0.035 seconds for compounded images. Unfortunately, most of these experiments have brought little unanimity in the results and have not compared, e. g., the apperception-times of very clever people with those of very slow and stupid ones. In the variety of perception lies the power of presentation (in our sense of the term). In the main other forces assist in this, but when we consider how the senses work in combination we must conclude that they determine their own ...
The speed of apperception has been subjected to measurement by Auerbach, Kries, Baxt, von Tigerstedt and Bergqvist, Stern
The results show 0.015 to 0.035 seconds for compounded images. Unfortunately, most of these experiments have brought little unanimity in the results and have not compared, e. g., the apperception-times of very clever people with those of very slow and stupid ones. In the variety of perception lies the power of presentation (in our sense of the term). In the main other forces assist in this, but when we consider how the senses work in combination we must conclude that they determine their own ...
