ON THE SEXUALITY OF THE FUNGI. 305 



It can scarcely be doubted that the protoplasm of a higher 

 plant, such as a phanerogam, diflfers from that of a lower cryp- 

 togam in being capable of doing more work; and that the 

 great advantage derived by a parasitic Fungus which has its 

 life so adapted that it can tax the cells of a phanerogamous 

 host plant, is that it obtains its food materials in a condition 

 more nearly approaching that of its own substance, than 

 would be the case if it had to work these materials up from 

 inorganic matters. 



Now it seems not improbable that the protoplasmic substance 

 of a higher phanerogam may contain so much energy, that it 

 can not only supply the vegetative mycelium of a parasitic 

 fungus with all that it requires for its immediate growth, 

 but also suffices to enable that fungus to store up enough 

 energy in its asexual or apogamous spores to last until the 

 next generation of the fungus gains its hold-fast on another 

 (and it may be distant) source of life-giving substance. 



Let us take the case of a uredinous fungus parasitic in 

 the leaves of a phanerogam. We know that the substances 

 necessary for the whole growth of the phanerogam are formed 

 in the cells of the leaf ; not only so, the matters which even- 

 tually find their place in the reproductive organs must be 

 formed there also, potentially at least. The leaf of a phane- 

 rogam so attacked, moreover, is able to support the parasitic 

 fungus for a long time uninjured, as I have convinced myself 

 by experiment, and there can be no doubt that substances 

 pass into the fungus which would normally have passed into 

 other parts of the host plant itself. Since these substances 

 serve to support the comparatively enormous display of energy 

 evinced in the growth, &c., of the phanerogam ; we need not 

 be surprised if they can also provide in addition for the parasite 

 for the time being. 



But we may imagine even this to fail after a time. With- 

 out speculating as to the possible differences eff'ective to a 

 mycelium which obtains enough to produce spores on one leaf, 

 which, germinating on another, produce a mycelium which 

 derives an advantage corresponding to that obtained by plants 



