Regeneration . that side makesnew cells. They found that the injured half is directly overgrownby the ectoderm from the developing half. When the material of theinjured blastomere is only incompletely reorganized, there is formed,after post-generation, an embryo that has a protrusion of yolk in thedorsal part of the body. When the injured material is completelyworked over, a perfectly formed embryo may result. The typicalhalf-embryos that Roux obtained were also obtained by Endres andWalter. They deny that whole embryos develop from one of thefirst two blastomeres, as Hertwig affirms. 222 REGE
Regeneration . that side makesnew cells. They found that the injured half is directly overgrownby the ectoderm from the developing half. When the material of theinjured blastomere is only incompletely reorganized, there is formed,after post-generation, an embryo that has a protrusion of yolk in thedorsal part of the body. When the injured material is completelyworked over, a perfectly formed embryo may result. The typicalhalf-embryos that Roux obtained were also obtained by Endres andWalter. They deny that whole embryos develop from one of thefirst two blastomeres, as Hertwig affirms. 222 REGENERA TION Hertwig repeated Rouxs experiment and obtained results entirelydifferent from those of Roux. He injured one of the first two blasto-meres of the frogs ^g^ with a hot needle, or by means of a galvaniccurrent. Hertwig states that after the operation the turns sothat the uninjured part lies uppermost. This is owing, he thinks, tothe appearance of a blastula or of a gastrula cavity in the developing. V
Size: 1440px × 1736px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublisherlondo, bookyear1901
