The same assumption must be made in regard to the Basidiomycetes among the Fungi, and for most of the Ascomycetes, for in these groups of Fungi sexual reproduction has only been demonstrated 'with certainty in a few genera.' That in these cases also there has been a degeneration of amphigony, until it has completely disappeared, seems probable from the two other groups of Fungi, the Zygomycetes and Oomycetes, since in these 'a reduction of sexuality amounting in some cases to complete disappearance' can be demonstrated even in existing forms. But whether it may be assumed that the Fungi which are now asexual are no longer capable of new adaptations, and whether their parasitic habit may be regarded as making up in some way for the lack of the remingling of the germ-plasm, as the botanist Möbius supposes, I am not able to decide. It is obvious that data in regard to amphimixis among the Fungi are still incomplete, and recent investigations lead us to suspect that sexual mingling may not be absent, but only disguised. Dangeard, Harold Wager, and others have observed that a fusion of nuclei precedes the formation of spores, and this may be regarded as amphimixis, although the conjugating nuclei belong to cells of the same plant and sometimes even to the same cell. But although we are here dealing with a set of facts which cannot yet be satisfactorily formulated in terms of our theory, it is nevertheless not contradictory to it that amphimixis should be wholly absent in the higher Fungi. But the fact would be contradictory to the unadulterated rejuvenescence-theory, for if amphimixis were really a condition of the continuance of life, no species--as we have already said--could continue to exist without it for countless generations. [Illustration: FIG. 38 (repeated). A fragment of a Lichen (_Ephebe kerneri_), magnified 450 times. _a_, the green alga-cells. _P_, the fungoid filaments. After Kerner.]