630 THE PHYLOGENY OF THE FUNGI 



tion, the naked, swimming cells being produced for multiplication. We 

 find this same trend of evolution in the fungi that we speak of as the 

 Lower Fungi. In the line of evolution of animals the contrary feature is 

 emphasized. The motile stage becomes more and more the prevailing one, 

 the encystment occurring only at the reproductive stage and finally dis- 

 appearing altogether. In some of the simple animals the plasma membrane 

 has become less firm and amoeboid motion is possible, together with the 

 amoeboid engulfment of food particles, yet even here encysted stages 

 may occur. 



We may perhaps assume that some of the chlorophyll-containing, one- 

 celled, naked, swimming organisms, whether we call them plants or not, 

 and which had possibly not yet reached the level of the present simplest 

 green algae, lost their power of producing chlorophyll and so had to 

 become parasitic in the tissues of animals or plants or saprophytic, feeding 

 upon the organic products of plant-like organisms. Among the group com- 

 monly called the Flagellata we find numerous examples of this type in 

 which the lack of chlorophyll is the chief distinguishing character. Also 

 such examples of lost chlorophyll occur among the true green algae, as for 

 example in Rhodochytrium, in which the carotinoid pigments are still pro- 

 duced although the chlorophyll has disappeared. This plant lives para- 

 sitically in the tissues of higher plants. Intermediate steps are found in 

 certain unicellular algae that still retain their chlorophyll but which are 

 obligate endophytes in aquatic higher plants. Examples of these are 

 Chlorochytrium and Eremosphaera. 



Phylogeny of Mycetozoa 



The Mycetozoa are characterized by their naked plasmodial vege- 

 tative stage and by the ultimate rounding up and encystment of the cells 

 as "spores," the only stage (with minor exceptions, such as the stalk cells 

 of Acrasiales) in which cell walls are found. With the exception of the few 

 described Acrasiales and Labyrinthulales, the encysted spores germinate 

 by production of anteriorly biflagellate swarm cells or sometimes one 

 flagellum seems to be lacking although two blepharoplasts are present. 

 These two fiagella are both of the whiplash type. The presence of flagel- 

 late, amoeboid planospores and inclination toward the formation of 

 Plasmodia or pseudoplasmodia is found also in some of the Protozoa 

 included in the Rhizopoda or Sarcodina and therefore it seems to the 

 author only reasonable to conclude that the Mycetozoa (in the broader 

 sense of this term) are derived from those organisms. Where they came 

 from remains to be determined but possibly the amoeboid Protozoa are 

 further developments of chlorophyll-less Flagellata. The Plasmodiopho- 

 rales are classified by Sparrow (1943) and some others in the Biflagellatae, 

 a group which includes also the Saprolegniales, Leptomitales, Lage- 



