title: [Epidermal ball cells of the Ascaphus truei Stejneger (Amphibia, Salientia, Ascaphidae) larva: a biometric contribution].
abstract: 1. With regard to orientation the in the larva of Ascaphus truei characteristic excretory special cell (mucosa cell) was analysed in plain preparations of epidermis from head-trune in four test regions - praeoral, postoral, craniodorsal and post spiracle -, the speciman (stage 32 according to Gosner 1960) being investigated was excellently fixed, 50 cells at times biometrically are used therefore. The element with adequate safety must be called ball cell because of its shape. 2. Elements only praeoral present a more little volume dividing from other average (and more unimportant occurence of an outlet). In respect of frequency distribution of different big ball cells in whole material significant differences are missed. A definite size of volume independent of region is prefered. 3. In 69% of all ball cells being considered there is an outlet, the existence is not fixed to a definite volume of cell. Shape of opening in 88% is round to a little ellipsoidal, its size is reaching to 10% more than half of maximal flat plain of cells; with regard to regions differences are absent. 4. In 3 regions thereupon being investigated (postoral, craniodorsal and post spiracle) a real correlation exists between height of single ball cells and thickness of epidermis.
mesh_terms: D000663:Amphibians / Q000033:anatomy & histology*; D000818:Animals; D001699:Biometry; D007814:Larva / Q000033:anatomy & histology; D012867:Skin / Q000166:cytology*
vernacular_title: Zur epidermalen Kugelzelle der Larve von Ascaphus truei Stejneger (Amphibia, Salientia, Ascaphidae): ein biometrischer Beitrag