Archive image from page 308 of The Danish Ingolf-expedition (1899-1953). The Danish Ingolf-expedition danishingolfex5cpt9daniuoft Year: 1899-1953 .-nJ m. Fig. 24. Stcenslrupia nulans. Longitudinal section of mouth tube (on the right hand side the section has passed a little awry). âo/rf. endoderm; f. gonad; m. mouth opening; n. wandering nematocj-st; n. bl. neniatoblasts; n. r. neniatocyst ring. â X 90. amount of protoplasm. This structure is a special development of the ectodermal cpithe- unicellular papillae on the apical projec- liuni, and it is (juite probable that sections of better
Archive image from page 308 of The Danish Ingolf-expedition (1899-1953). The Danish Ingolf-expedition danishingolfex5cpt9daniuoft Year: 1899-1953 .-nJ m. Fig. 24. Stcenslrupia nulans. Longitudinal section of mouth tube (on the right hand side the section has passed a little awry). âo/rf. endoderm; f. gonad; m. mouth opening; n. wandering nematocj-st; n. bl. neniatoblasts; n. r. neniatocyst ring. â X 90. amount of protoplasm. This structure is a special development of the ectodermal cpithe- unicellular papillae on the apical projec- liuni, and it is (juite probable that sections of better preserved material will reveal ner- tjââ _ . vous elements at the base of these cells. On the whole, the epitheHum of the exumbrclla is uncommonly strongly developed in this species, the cells being nearly cubical, and traces of unicellular 'papillae' being found in scattered groups anywhere on the surface, though not so conspicuously developed as on the apical jjrojection. As in the case of Eup/iysa, Hartlaub states in the dia- gnosis of the 'subgenus' Stcenslrupia that the mouth lacks an armature of nematocysts. As a matter of fact, the distal part of the mouth tube is encircled by a well-developed, fairly prominent ring of high ectodermal cells, very much vacuolated, and strongly armoured with nematocysts of two different kinds, a large number of small ones and a less number two or three times the size of the first (see textfig. 24). Nematocysts are developing in great numbers in the endoderin of the proximal part of the mouth tube, where they are found in all stages within a well-defined, ring-shaped zone. There is much evidence that the fullv developed nematocysts wander from this zone outwards F'ig. 25. Sleenslrupia nutans. along the inner side of the .supporting lamella, turn round the edge of the latter. Transversal section of proxi- , , , . , ⢠,- , 1 â ii i. 1 iiial part of female manu- and thus reach into their final place m the ectoderm. . . ._ As to the
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Keywords: 1890, 1899-1953, archive, arctic_regions, book, bookauthor, bookdecade, bookpublisher, booksubject, bookyear, copenhagen_h_hagerup, danish_ingolf_expedition_1895_1896_, drawing, historical, history, illustration, image, k_benhavns_universitet_zoologisk_museum, marine_animals_arctic_regions, page, picture, print, reference, scientific_expeditions, vintage
