The study of the specific functions of the various tissues) by Schwendener (,Das mechanische Princip un Ban der Monocotylen, 1874, and other works), followed by numerous pupils and others, among whom Haberlandt (Physiologische Pfianzen-Anatomie, Leipzig, 1st ed., 1884, 4th ed., 1909, and other works) is pre-eminent.
In 1869 Schwendener put forward the really illuminating view - exactly opposite to that of Baranetzkythat the gonidia in all cases were algae which had been attacked by parasitic fungi.
Although Schwendener supported this view of the " dual " nature of lichens by very strong evidence and identified the more common lichen-gonidia with known free-living algae, yet the theory was received with a storm of opposition by nearly all lichenologists.
The observations of Schwendener, however, received ample support from Bornet's (1873) examination of 60 genera.
Gyro- phora), and even After Schwendener, from De Bary's Vergleichende Mor s t i p i t a t e (e.g.
Schwendener, Die Algentypen der Flechtengonidien (Basel, 1869); A.