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abnormal absent alveolus Anat animals antenna apex appendages arising articulation bears bilaterally bone brachial plexus Brit canine carpus cervical cervical ribs claws colour condition connexion cuneiform described developed discontinuous division dorsal dorsal fin double duplicity evidence examples external extra digit extra legs extra tooth eye-spots fact femur figure fore foot given hallux Homoeosis hoof incisors internal left side limb lower jaw lumbar male mamma manus Meristic Variation metacarpal metatarsal middle line minimus molar nerves nipples normal leg occur ocelli organs pair phalanges placed plane plates plexus pollex polydactyle position posterior premolar present radial relation repetition ribs right side rudimentary Secondary Symmetry seen segments separate shew shewn in Fig similar single skulls species specimen spinal nerves spurs structure supernumerary supernumerary nipples syndactylism tarsi tarsus teeth three phalanges tibia toes transverse processes upper jaw usual ventral surface vertebra wing Zool
Page 5 - According to both theories [the Lamarckian and the Darwinian] specific diversity of form is consequent upon diversity of environment, and diversity of environment is thus the ultimate measure of diversity of specific form. Here, then, we meet the difficulty that diverse environments often shade into each other insensibly and form a continuous series, whereas the specific forms of life which are subject to them on the whole form a discontinuous series.
Page 3 - For though on the whole the offspring is like the parent or parents, its form is perhaps never identical with theirs, but generally differs from it perceptibly and sometimes materially. To this phenomenon, namely, the occurrence of differences between the structure, the instincts, or other elements which compose the mechanism of the offspring, and those which were proper to the parent, the name Variation has been given.
Page 79 - hairy" variety of the moorhen became established on an island, as many strange varieties have been, I do not doubt that ingenious persons would invite us to see how the hairiness fitted the bird in some special way for life in that island in particular. Their contention would be hard to deny, for on this class of speculation the only limitations are those of the ingenuity of the author. While the only test of utility is the success of the organism, even this does not indicate the utility of one part...
Page 16 - We have seen that the differences between Species on the whole are Specific, and are differences of kind, forming a discontinuous Series, while the diversities of environment to which they are subject are on the whole differences of degree, and form a continuous Series; it is therefore hard to see how the environmental differences can thus be in any sense the directing cause of Specific differences, which by the Theory of Natural Selection they should be.
Page 61 - Material an, das in erster Linie zeigen sollte, daß diese Erscheinungen diskontinuierlich verlaufen, dh nicht durch Übergänge mit der Ausgangsform verbunden seien. Er sagt dazu an einer Stelle (S. 61, Auflage 1894): „We have said that the variation is discontinuous, meaning thereby that the change is a large and decided one, but it is more than this; it is not only large, it is complete.
Page 479 - The nearer of the two extra appendages is in structure and position formed as the image of the normal appendage in a plane mirror placed between the normal appendage and the nearer one, at right angles to the plane of the three axes; and the remoter appendage is the image of the nearer in a plane mirror similiarly placed between the two extra appendages.
Page 539 - In regard to the first category, no authentic case is known which conforms to it. In every case so far recorded "no right arm is ever succeeded on the same side of the body by another arm properly formed as- right and no crustacean has two right legs in succession, where one should be
Page 568 - Variation, that is to say, of new forms having from their first beginning more or less of the kind of. perfection that we associate with normality, is a fact that disposes, once and for all, of the attempt to interpret all perfection and defmiteness of form as the work of Selection.