A Monograph of the Myxogastres. 17 



the Tuleraceae and the Elaphomycetae originate as masses of 

 swarm-cells, which after passing through various phases, assume 

 the well-known ascigerous form, and that these groups, if kept 

 in the fungi at all, must be placed with the Mycetozoa. He 

 further considers that the typical members of the Hymenoyastreae 

 and the Lycoperdeaccae present similar characteristics in the 

 earliest condition. If corroborated, the above statement will 

 show how imperfect and superficial has been all previous work 

 on these groups. 



The following remarks by Mr. A. Lister are considered by the 

 author as favouring the animal nature of the Myxogastres ; but 

 as usual, the evidence is afforded entirely by the vegetative 

 phase, and consequently still much in -touch with their aquatic 

 progenitors, the Flagellatae, whereas the individuality of the 

 Myxogastres, as it appears to me, is to be found in the repro- 

 ductive phase, and further, the individuality is obviously due 

 in main to the change from an aquatic to an aerial habitat. 

 In all probability the sexual method by conjugation was the 

 one followed by the aquatic primitive forms, and if so, we find 

 an agreement more or less pronounced with the ferns, where 

 the prothallus, the sexual organ of reproduction, is structurally 

 in touch with the aquatic forms from which this group is 

 supposed to have evolved, whereas the truly aerial spore-pro- 

 ducing form is the portion that gives most individuality to the 

 ferns. 



"At a meeting of the Linnean Society in April 1889, I 

 described the mode of feeding which I had observed in the 

 swarm-cells of Stemonitis fusca. I have since been able to 

 watch the same process in the swarm-cells of several other 

 species. Those of Pcrichaena corticalis afforded an interesting 

 instance, because of the great activity of the bacilli which 

 abounded in the preparation, and as showing the voracity of a 

 few individual swarm-cells.' One was noticed which already 

 contained four vacuoles stuffed with bacilli, probably six to 

 eight in each. It was observed to throw out several long 

 pseudopodia from the posterior region, to which active bacilli 



became attached. In the course of twelve minutes four were 



c 



