United States or Venezuela ? Vote for the TOP Country of the Week !
Any one can subscribe to these statements; in truth they contain something totally different from the "biogenetic principle"; for Haeckel has really no interest in so general a truth, but is intent only upon a proof of Descent. Hertwig continues: "In order to make our train of thought clear, let us take the egg-cell.
This is a very resigned position, very far removed from Haeckel's certainty and orthodoxy. To sum up: O. Hertwig has become a serious heretic in matters Darwinian. Will Haeckel, in his usual manner try to cast suspicion on Hertwig also?
This is a view which has frequently been clearly expressed by anti-Darwinians: The egg-cells of the various animals are in themselves fundamentally different and can therefore have nothing in common but similarity of structure. In opposition to Hertwig, Haeckel in his superficial way deduces from it an internal similarity as well.
With the microscope at his eye, he magnifies nature's mysteries; he sums up the investigations of the Hertwig brothers; he discourses learnedly of the nucleolus of the Cytula or progeny cell. He declares that science is able to watch the creation of a human being, as it watches the progress of a chick in the egg.
The next important work was that of Richard Hertwig, who inclined to think that these cells sometimes developed from the protoplasm of the Radiolarian, and failing to verify the observations of Cienkowski, maintained the opinion of Haeckel that the yellow cells "fur den Stoffwechsel der Radiolarien von Bedeutung sind."
The principles of the new school are very widespread to-day, but we cannot here follow their development in the works of individual investigators, such as Reinke, R. Hertwig, O. Hertwig, Wiesner, Hamann, Dreyer, Wolff, Goette, Kassowitz, v. Wettstein, Korschinsky, and others. The Spontaneous Activity of the Organism.
Hertwig agrees with Schopenhauer and Lotze in regarding every primitive natural “force” as unique, not reducible to simpler terms, but qualitatively distinct,—a “qualitas occulta,” capable not of physical but only of metaphysical explanation. And thus his conclusions imply rejection of mechanism in the cruder sense. As such, it has only a very limited sphere of action in the realm of the living.
It is worthy of special note in this connection that Hertwig likewise evidently regards as the sole really empirically and inductively serviceable proof of Descent, that which is drawn from palaeontology, from prehistoric animal and plant remains.
Haeckel had already compared the yellow cells of Radiolarians to the so-called liver-cells of Velella; but the brothers Hertwig first recalled attention to the subject in 1879 by expressing their opinion that the well-known "pigment bodies" which occur in the endoderm cells of the tentacles of many sea-anemones were also parasitic algae.
Says Hertwig: "Protoplasm is not a single chemical substance, however complicated, but a mixture of many substances, which we must picture to ourselves as finest particles united in a wonderfully complicated structure." Truly protoplasm is, to borrow Mephistopheles' expression concerning blood, a "quite peculiar juice."
Word Of The Day