The Shipley Collection of Scientific Papers, Volume 331890 - Zoology |
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Page 44
... opening can be represented by two independent perforations is shown by Echinoderm development . Thus in Holothurians the larval mouth by a shift of position becomes the adult ; in Asterids and Echinids , on the other hand , it is ...
... opening can be represented by two independent perforations is shown by Echinoderm development . Thus in Holothurians the larval mouth by a shift of position becomes the adult ; in Asterids and Echinids , on the other hand , it is ...
Page 44
... opening such as is found at the present day in the Actinozoa . 2. That the somites of segmented animals are derived from a series of pouches of the primitive gut ( archenteron ) of a Colenterate - like ancestor , i . e . from pouches ...
... opening such as is found at the present day in the Actinozoa . 2. That the somites of segmented animals are derived from a series of pouches of the primitive gut ( archenteron ) of a Colenterate - like ancestor , i . e . from pouches ...
Page 44
retained its posterior opening into the alimentary canal while the external pores have been lost . I now add to these three propositions a fourth . 4. That the trachea are not developed from cutaneous glands of a worm - like animal with ...
retained its posterior opening into the alimentary canal while the external pores have been lost . I now add to these three propositions a fourth . 4. That the trachea are not developed from cutaneous glands of a worm - like animal with ...
Page 44
... opening , the definite blastopore , by the closure of the lip of the slit except at one point . The point at which it remains open must depend on the shape of the larva , & c . , and will obviously be determined by the convenience of ...
... opening , the definite blastopore , by the closure of the lip of the slit except at one point . The point at which it remains open must depend on the shape of the larva , & c . , and will obviously be determined by the convenience of ...
Page 44
... opening is elongated , and the animal is symmetrical on each side of the long axis of the mouth . At one end of the long axis the mouth is especially differentiated , and this differentia- tion exteuds down the stomodæum as a strongly ...
... opening is elongated , and the animal is symmetrical on each side of the long axis of the mouth . At one end of the long axis the mouth is especially differentiated , and this differentia- tion exteuds down the stomodæum as a strongly ...
Common terms and phrases
acquired characters Actinozoa adult alimentary Amphioxus Anatomy ancestral Annelid ants appear archenteron assume become blastopore body Burchell's zebra carapace-length cavity changes chromatin cœlom colour connection corpuscles degeneration dentary derived deviation differentiation diploblastic disuse division ectoderm eggs embryo essay evolution excretory existence explanation fact females fibres formation frontal breadth germ germ-plasm growth homologous horse hybrid hypothesis important insects instance instincts larva larvæ legs less males mare mean mesoblast Metazoa modified morphological mouth and anus natural selection nephridia nervous system neural canal nucleus number of glands nutrition observations occur ontogeny organs origin ovum Panmixia Peripatus plants plasm pores pouches present primitive streak principle produced Professor Weismann protoplasm recognised regard reproductive cells result Schwann Sedgwick segmentation nucleus segmented animals somites specialised species Spencer stage structure substance supposed telegony theory tion tissues unicellular variability variations Vertebrata Vertebrate workers yolk zebra
Popular passages
Page 65 - The elementary parts of all tissues are formed of cells in an analogous, though very diversified manner, so that it may be asserted, that there is one universal principle of development for the elementary parts of organisms, however different, and that this principle is the formation of cells.
Page 7 - XVIII. OF THE SCHEMATISME OR TEXTURE OF CORK, AND OF THE CELLS AND PORES OF SOME OTHER SUCH FROTHY BODIES...
Page 72 - PROCESSES, AND COLLATERAL INFORMATION IN THE ARTS, MANUFACTURES, PROFESSIONS, AND TRADES, INCLUDING MEDICINE, PHARMACY, AND DOMESTIC ECONOMY ; designed as a General Book of Reference for the Manufacturer, Tradesman, Amateur, and Heads of Families.