| Author Title Journal |
Bresslau E (1928) Zum Problem der Fibrillen-bildung. Entstehung von Fasern durch Zug im lebenden Organismus. Zool Jahrb Abt Allgem Zool U Physiol Tiere 45: 707-716 |
Abstract / Notes
While studying the huge egg capsules, 8-9 mm. in diameter, containing 5-8 embryos, of a new land planarian from Brazil of the genus Geoplana (resembling G. rufiventris, but not named) it was noted that the yolk hung in strings from the embryos. About the 3rd day of development, the embryos develop a provisional embryonic pharynx which ingests the yolk cells by powerful sucking movements. This sucking action carried out by the several embryos in the capsule arranges the yolk cells in strings and strands readily noted on dissection. Sections show that these yolk strands, passing into the embryonic pharynges, consist of actual fibrils. The fibrillar structure disappears as soon as the yolk reaches the interior of the embryo. The author concludes that the tension exerted 8 by the sucking pharynges induces fibril formation and compares this observation with the work of Ebner and Giersberg on the experimental production of fibrils by tension.| Home page -- (Main hierarchy) |