INBEEEDING, PARTHENOGENESIS, ASEXUAL KEPEODUCTIOX 261 



as making up in some way for the lack of the remingling of the 

 germ-plasm, as the botanist Mobius 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 rejuve- 



Pie. 38 (repeated). A fragment of a Lichen {Ephehe Icerneri), magnified 450 

 times, a, the green alga-cells. P, the fungoid filaments. After Kerner. 



nescence-theory, for if amphimixis were really a condition of the 

 continuance of life, no species — as we have ah'eady said — could 

 continue to exist without it for countless generations. 



The same argument holds true for the higher plants, which have 

 become purelj^ asexual under the influence of cultivation. I refer to 

 many of the well-marked varieties of our cultivated plants which 

 multiply exclusively, or almost exclusively, by means of tubers and 

 slips, as is the case with the potato, the manioc, the sugar-cane, the 

 arrowroot-plant (Maranta ariindinacea), and others. All these facts 

 can easily be reconciled with our interpretation of the meaning of 

 amphimixis, although the attempt to range them as evidence against 

 our theory has more than once been made. We have thus arrived at 

 the conclusion that while many-sided adaptations, that is, variations 



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