This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1906 Excerpt: …in the conidium the two nuclei fuse. This is Dangeard’s idea of a sexual act; however, apart from this special point, the fact remains that this method of rejuvenescence may already exist in the conidial form of a species which yet retains the older ascigerous form of fruit. If we once more contrast the evolution of chlorophyll bearing plants with that of the fungi, the superiority of the former from both a morphological and physiological standpoint is at once evident, as compared with the fungi. In both groups the primitive sexual generation–as a distinct and independent structure–has gone in the higher forms, but in chlorophyllose plants it was, as it were, absorbed by the newer sporophyte generation, and its primitive functional activity retained. It is this retention of the means of sexual reproduction that has enabled the sporophore generation of chlorophyllose plants to attain their present development. Ample proof of this idea is illustrated by the difficulty experienced in perpetuating plants reproduced by asexual or vegetative methods alone, as potatoes, etc. The fungi, on the other hand, through inability to incorporate the sexual phase with the new aerial conidiophore, have failed to evolve morphologically beyond the primitive hyphal element; there is no vestige of a tissue, as understood in phanerogamic structures, present in the highest forms. The evolution of nuclear fusion, as demonstrated by Dangeard, has saved the fungi from actually disappearing, but it has proved incapable of enabling them to assert themselves, thus demonstrating its inferiority as compared with true sexual reproduction. II. PATHOLOGY DISEASE CAUSED BY FUNGI Obligate parasites have been shown by Brefeld to be not under all conditions absolutely dependent on the pr…