Category: Science - Chemistry/Biochemistry
1. The physical researches of the last ten years have put the atomistic theory of matter and electricity on a definite and in all probability permanent basis. We know the exact number of molecules in a given mass of any substance whose molecular weight is known to us, and we k...
1. The physical researches of the last ten years have put the atomistic theory of matter and electricity on a definite and in all probability permanent basis. We know the exact...
7. v. Uexküll supposes as did Claude Bernard and as does Drieschthat in an organism or an egg the ultimate processes are purely physicochemical. In an egg these processes are guided into definite parts of the future embryo by the Mendelian f...
8. CHAPTER II1. Each organism is characterized by a definite form and we shall see in the next chapter that this form is determined by definite chemical substances. The same is true for crys...
9. CHAPTER III1. It is a truism that from an egg of a species an organism of this species only and of no other will arise. It is also a truism that the so-called protoplasm of an egg does not...
10. CHAPTER IV1. We have become acquainted with two characteristics of living matter: the specificity due to the specific proteins characteristic for each genus and possibly species and the s...
11. CHAPTER V1. The majority of eggs cannot develop unless they are fertilized, that is to say, unless a spermatozoön enters into the egg. The question arises: How does the spermatozoön caus...
12. Chapter III) will also induce membrane formation, and that theessential feature in the causation of development is a cytolysis of the superficial or cortical layer of the egg. As soon as this layer is destroyed the development of the egg c...
13. CHAPTER VI1. The writer in a former book (_Dynamics of Living Matter_, 1906, p. 1), defined living organisms as chemical machines consisting chiefly of colloidal material and possessing t...
14. CHAPTER VII1. The action of the organism as a whole seems nowhere more pronounced than in the phenomena of regeneration, for it is the organism as a whole which represses the phenomena of...
15. CHAPTER VIII1. It is a general fact that both sexes appear in approximately equal numbers, provided a sufficiently large number of cases are examined. This fact has furnished the clue for t...
16. Chapter IV), in others they are formed successively, very often thespermatozoa appearing first (protandric hermaphroditism). In the long tapeworm _Tænia_ each ring has testes and ovaries, but the young rings are only male while in the older rin...
17. CHAPTER IX1. The scientific era of the investigation of heredity begins with Mendel’s paper on plant hybridization which was not appreciated by his contemporaries. Mendel invented a metho...
18. CHAPTER X1. The idea that the organism as a whole cannot be explained from a physicochemical viewpoint rests most strongly on the existence of animal instincts and will. Many of the inst...
19. CHAPTER XI1. The term environment in relation to an organism may easily assume a mystic rôle if we assume that it can modify the organisms so that they become adapted to its peculiarities...
20. CHAPTER XII1. It is assumed by certain biologists that the environment influences the organism in such a way as to increase its adaptation. Were this correct it would not contradict a pure...
21. CHAPTER XIIIDarwin’s work has been compared to that of Copernicus and Galileo inasmuch as all these men freed the mind from the incubus of Aristotelian philosophy which, with the efficient...
22. CHAPTER XIV1. It is an old saying that we cannot understand life unless we understand death. The dead body, if its temperature is not too low and if it contains enough water, undergoes rap...
23. v. Dungern, 8024. v. Körösy, 300Regeneration, 9 ff., 153 ff.; in plants, 160 ff.; in _Bryophyllum_, 161-167; in animals, 167 ff.; in _Tubularia_, 167-170; in _Cerianthus_, 171 ff.; in Planarians, 173-176; in _...