The contribution has the purpose to recapitulate former author’s knowledge on the problems of the spectral investigation of optical properties of weakly absorpting optical materials, which the author gathered during the research of optical materials for infrared spectral region. The author reflects the recent article in this journal [5], and furthermore expands and generalizes questions solved within. Spectral investigations should guide to determine of material parameters, particularly the refractive index and the absorption coefficient. Not a little attention is devoted to the used terminology when the author prefers the Czech language terms. and Tento příspěvek má za cíl shrnout dřívější poznatky autora o problematice spektrálního vyšetřování optických vlastností slabě pohlcujících optických materiálů, které autor získal při výzkumu optických materiálů pro infračervenou oblast spektra. Autor tak reaguje na nedávný článek v tomto časopise [5] a otázky v něm řešené dále rozvíjí a zobecňuje. Spektrální vyšetřování mají vést ke stanovení materiálových parametrů, zejména indexu lomu a součinitele pohlcení. Nemalá pozornost je věnována také používané terminologii,v níž autor dává přednost českým termínům.
Daniconema anguillae Moravec et Koie, 1987 larvae measuring 1.64-1.76 mm were occasionally found in considerable numbers in the fins and subcutaneous connective tissue of approximately 50% of eel Anguilla anguilla (L.) sampled from Lake Balaton, Hungary. The larvae were noted for their slender body, very long tail with a rounded tip, a densely transversely striated cuticle, and the presence of boring tooth and large kidney-shaped amphids on the cephalic end. The larvae could easily be recovered from the above mentioned organs by placing them into isotonic saline solution. No disease signs or pathological changes attributable to the larval infection could be observed. The only histological indication of host reaction was the appearance of macrophages adhering to the body surface of larvae and of cells with spherical nucleus in areas around the larvae. A possible life cycle pattern of I), anguillae is discussed.