Presidential Address. F. T. Brooks. 2i 



of the plant and the animal kingdoms there are large numbers 

 of forms which in some respects show plant characteristics and 

 in others, animal characteristics, i.e. are intermediate between 

 the plant and animal kingdoms, as well as innumerable other 

 types which, though predominantly plant or animal-like, can 

 scarcely be regarded as definitely one or the other. The Fla- 

 gellata, the Mycetozoa, and the Bacteria are groups of this 

 class. Some of the Flagellata are intermediate in character 

 between plants and animals, while others possess almost ex- 

 clusively animal characteristics. The Mycetozoa are pre- 

 dominantly animal-like in one phase of their existence, and 

 plant-like at another, while the Bacteria are chiefly plant-like 

 throughout their development. \\Tiatever \iew is taken of the 

 origin of protoplasm, i.e. of life on this planet, it is clear, from 

 what is known of evolutionary processes, that at the da\\Ti of 

 life the forms were probably very few, perhaps only one, 

 possessing a mode or modes of nutrition conceivably different 

 from those of the great majority of plants and animals of the 

 present day. Certain forms of bacteria obtain their essential 

 supplies of nitrogen and carbon even now by ways which are 

 neither hke those of typical plants nor animals. It is possible, 

 therefore, that the earhest forms of life were generahsed types, 

 neither definitely plants nor animals, perhaps possessing peculiar 

 prototrophic modes of nutrition. I mention this possibility as 

 it is sometimes postulated that plant forms must have preceded 

 the evolution of animal organisms. Xow it is likely that long 

 before organisms possessing tissue systems had become differ- 

 entiated, the chief groups of the Protista had come into existence, 

 so that there was no lack of organisms of a saprophytic mode 

 of nutrition available in the sea at the time when the larger 

 seaweeds were being evolved. It is less difficult to conceive of 

 the direct evolution of such unicellular types into forms \nth 

 hyphae as a response to continued possibilities of existence in 

 vegetable and animal debris, than it is to suppose that the 

 fungi have in the main been evolved directly either from 

 transmigrant algae, or from Green and Red algae somewhat 

 similar to existing types. The fungi undoubtedly possess some 

 of the initial, evolutionary impetus characteristic of all the 

 primary groups of li\-ing organisms, which they hold by virtue 

 of an early differentiation from protist organisms. 



One of the difficulties encountered by those who derive the 

 fungi from the algae is to account for the Chytridiineae from an 

 algal ancestry. There are few algae to which these peculiar fungi 

 can be even remotely associated, and the group contains several 

 families of great diversity. The simplest t\^es are approximately 

 spherical with no attempt at proliferation, but other forms 



