574 WESTON 



ing the millions of years these natural substances have been available as sub- 

 strata for the degrading activities of thousands of diverse and physiologically 

 potent fungi, the probablility seems strong that in time some fungi will achieve 

 the active degradation of man-made materials seemingly invulnerable at 

 present. 



Together with the general progress briefly and cursorily indicated above, 

 some of the advances in Mycology have been more striking and spectacular 

 in their contribution to various significant and productive areas of Biology. 

 Of the many instances of such contributive service, the time available here 

 may permit consideration of four examples especially representative and note- 

 worthy. The first example is the contribution of Mycology to the field of 

 morphogenesis, of organization, and the controls which govern size and form 

 and development in organisms. In this area, during the early part of this 

 fifty-year period, the use of zoological material dominated the field, and the 

 botanists whose work was almost exclusively confined to higher plants, al- 

 though contributing some highly significant results, were handicapped because 

 the significant and critical early stages of development were enclosed within 

 the complicated structure of the parent plant rather than freely accessible as 

 in the egg, or blastula, or gastrula of certain animals. The situation shifted with 

 dramatic suddenness, however, about twenty-five years ago, when K. B. 

 Raper, stimulated by the potentialities implicit in the pioneer work of Olive 

 and Harper and equipped with his increasingly expert knowledge of the 

 simpler aggregating types of slime molds, began his illuminating studies of 

 these especially advantageous organisms. Their advantages are inherent in 

 the regular sequence of well-defined stages in the life cycle, as follows: from 

 the germination of the spores and the feeding and multiplication of the 

 amoeba-like swarmers to which they give rise, onward through the assembling 

 of these in definite centers of aggregation with, in the case of some, a migra- 

 tion of the resulting pseudoplasmodium, to finally the ultimate phase of 

 culmination, in which the originally totipotent swarmers differentiate into 

 stalk cells and spores in the construction of a simple but effective fructifica- 

 tion. The whole life cycle is thus a dedication to the objective of producing 

 the numerous hardy spores in a position favorable for efficient distribution. 

 Intensive and ingenious investigations, chiefly by K. B. Raper and John T. 

 Bonner, have contributed materially toward our understanding of fundamental 

 aspects of organization and the control of development in this cycle and have 

 given these simple organisms a place of prominence in morphogenetic investi- 

 gation. Also, they have channeled renewed research interest tov/ard the 

 myxobacteria and myxogastralean slime molds which achieve comparable 

 fruiting bodies by constructional procedures different enough to promise still 

 further information on the morphogenetic mechanisms involved. 



As a second example, the contribution of Mycology to a broader under- 

 standing of some of the fundamental features of sex and sexuality may be 



