3o6 INTRODUCTION TO THE STUDY OF FUNGI 



groups are formed by the close approach of two or more of 

 these bodies ; these groups often disperse again, but eventually 

 the components of a group coalesce, and lose their individuality ; 

 this coalescence and loss of individuality results in the forma- 

 tion of a small plasmodium, which, in some unknown way, 

 possesses the power of attracting surrounding free swarm-cells ; 

 these at once coalesce and add to the bulk of the plasmodium. 

 The nuclei of the component swarm -cells retain their in- 

 dividuality in the plasmodium, the latter retaining the power 

 of motion originally possessed by its components, and represent 

 the vegetative phase of a Myxogaster. Under certain con- 

 ditions, unfavourable for active vegetative work, plasmodia 

 possess the power of passing into a temporary sclerotioid, or 

 resting stage ; the preliminaries for this condition are the 

 breaking up of the protoplasm into innumerable roundish or 

 polyhedric cells. In some species the cells become surrounded 

 by a distinct, colourless membrane, which shows the reaction 

 of cellulose." 



From the above account we learn that the coalescence of 

 naked motile cells, or even the aggregation of naked motile 

 cells without loss of individuality, is, from De Bary's standpoint, 

 the proof that the Myxogasters are not plants. 



After comparison of these phenomena with similar analogous 

 instances in the Phycomycetes and other Fungi, the following 

 reasons are adduced in support of the vegetable, rather than 

 animal, nature of these organisms : — 



(1) Frequent presence of cellulose in the general membrane 

 protecting plasmodia, cell-walls of spores, sporangia, and walls 

 enclosing the protoplasm in the sclerotioid, or resting stage of 

 plasmodia. (2) Presence of germ -pores in the cell- walls of the 

 spores, of some species. (3) The frequent separation of lime 

 from the protoplasm at the commencement of the reproductive 

 phase. (4) The frequent separation of a substance from the 

 protoplasm during the period of spore -formation, homologous 

 with the substance separated during the same period in the 

 Ascomycetes, etc. This substance in the Myxogasters forms 

 the capillitium. (5) The agreement with many Fungi in the 

 contrivance for spore dissemination. (6) The production by 

 free cell-formation of spores protected in the early stage with 



