. The British freshwater Rhizopoda and Heliozoa. oda, after the application of reagents, an ap-parent separation into different, plasma-layers occurs,these may be definitely regarded as artificially produced,in face of the conviction arrived at during the life ofthe animal. Gruber supports his view by a reference to PeJovn/xa * Atti Soo. Ital. Soi. xix, fasc. 4 (1876).t Morphol. xi (1886). 6 BRITISH FRESHWATER RHIZOPODA. and certain of the Amaibse, in which often no ectoplasmcan be distinguished. Under certain circumstanceseven here, such a hyaline external plasma-layer makesits
. The British freshwater Rhizopoda and Heliozoa. oda, after the application of reagents, an ap-parent separation into different, plasma-layers occurs,these may be definitely regarded as artificially produced,in face of the conviction arrived at during the life ofthe animal. Gruber supports his view by a reference to PeJovn/xa * Atti Soo. Ital. Soi. xix, fasc. 4 (1876).t Morphol. xi (1886). 6 BRITISH FRESHWATER RHIZOPODA. and certain of the Amaibse, in which often no ectoplasmcan be distinguished. Under certain circumstanceseven here, such a hyaline external plasma-layer makesits appearance, and this consequently must from the granular plasma in the way inwhich, locally bounded, a hyaline pseudopodium isevolved from the body of a Rhizopod consisting ofgranular plasma. Concerning the external limita-tions of the Rhizopod body, he says that it is naked,but it would appear that by contact with water, asDr. Wallich had previously shown, a stiffening of theplasma takes place at the periphery, preventing its. Fig. 1.—Portion of the periphery of Pelomyxa palustris when atrest, with the endoplasm {en) and ectoplasm (ec) sharply definedas frequently seen, and an outer fringe of minute projectionsfrom the latter, x about 150. deliquescence, and also causing an immediate closureof the cut surface, in case of artificial division. Whenthe protoplasmissues forth in a broad process, in theform of pseudopodia, the former bounded portion dis-solves in the advancing plasma, to become re-formed atthe same moment. This author acknowledges the prior claim of to the discovery. Dr. Wallich was also thefirst to explain the production of the nutritive vacuoles,by assuming that a drop of water is carried in alongwith the incepted food-particles, and that this exertsthe known stiffening action upon the portions of plasmasurrounding the bodies incepted, so that every nutritivevacuole ap])ears to be lined with an ectosarcal layer. INTRODUCTION. 7 The
Size: 1203px × 2078px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauth, bookcentury1900, bookdecade1900, bookidcu31924000623961
