The Shipley Collection of Scientific Papers, Volume 621901 - Zoology |
Common terms and phrases
acquired adult altre Amphioxus ancestral ancora andere animali animals asexual asexual reproduction become biological birds body century characters colour conjugation consciousness Crustacea Cuvier Darwin degeneration differentiation disease ectoderm effect electric embryo embryology Entwickelungslehre Eurypterida evolution experiments external fact fauna fish fisheries food yolk fresh-water galvanometer gametes germ cells germ layers germ-cells Geschichte groups heeft idioplasm important individual inheritance investigation knowledge l'uomo laboratory Lake larva larvæ living lotta ment Metazoa modification muscle nature niet observations offspring organs origin ovum Oxford parent Paris parthenogenesis pathological phenomena Phylogenie Physiologie poco present primitive problems produced protoplasm Protozoa quali question regard reproduction response Roger Bacon scientific sexual reproduction species spermatozoon stage stations statoblasts stimulus strijd structure Systematik telegony theory tion tissues unserer uomo vergleichenden Anatomie vertebrates Weismann zich zijn Zool Zoologie zoologischen Zootomie zygote
Popular passages
Page 3 - In my opinion the greatest error which I have committed, has been not allowing sufficient weight to the direct action of the environment, ie food, climate, etc, independently of natural selection.
Page 32 - Darwin, clearly realising that variation occurs in many different directions, arrived at the far-reaching conclusion that the best adapted varieties are selected by the environment, and thus have a chance of giving rise to new species. Though impressed with the paramount importance of selection, Charles Darwin realised that ' its action absolutely depends on what we in our ignorance call spontaneous or accidental variation.
Page 15 - Before the advent of relativity, physics recognized two conservation laws of fundamental importance, namely, the law of the conservation of energy and the law of the conservation of mass; these two fundamental laws appeared to be quite independent of each other.
Page 14 - Thy shadow, and the darkness of thy steps, And my heart ever gazes on the depth Of thy deep mysteries. I have made my bed In charnels and on coffins, where black death Keeps record of the trophies won from thee, Hoping to still these obstinate questionings Of thee and thine, by forcing some lone ghost Thy messenger, to render up the tale Of what we are.
Page 7 - How this was possible any one will readily understand who knows from his own experience how great the value of personal observation is for the development of independent and unprejudiced thought. For a young man who, besides collecting a rich treasure of positive knowledge, has practised dissection and the exercise of a critical judgment, a long sea-voyage and a peaceful sojourn among entirely new surroundings afford an invaluable opportunity for original work and deep reflection. Freed from the...
Page 15 - That the parts of the cerebrum have different functions ; and that the nerves which we trace in the body are not single nerves possessing various powers, but bundles of different nerves, whose filaments are united for the convenience of distribution, but which are distinct in office, as they are in origin from the brain...
Page 8 - OWEN.— LECTURES ON THE COMPARATIVE ANATOMY AND PHYSIOLOGY of the VERTEBRATE ANIMALS, delivered at the Royal College of Surgeons in 1844 and 1846.