INTEODUCTION. 1 7 



amoeboid movements, but do nob produce a flagellum, and aggregate 

 without coalescing into a true plasmodium, has already been 

 referred to (p. 1). The view held by de Bary that the Mycetozoa 

 are more closely associated with the Protozoa is supported by a 

 comparison with the pelagic Frotomyxa of Haeckel, which is 

 stated to develop a plasmodium by the coalescence of swarm- 

 spores, and differs from the Mycetozoa chiefly in the absence of 

 a firm spore membrane ; * also by comparison with Bursulla, 

 which, according to Sorokin, forms a true plasmodium and minute 

 sporangia on horse dung ; the spores do not become invested with 

 a firm membrane, and escape from the swollen apex of the 

 sporangium in the form of swarm-cells, without cUia, but capable 

 of amoeboid movement.f Zopf extends the Mycetozoa so as;^to 

 embrace the Monadinece of Oienkowski, but de Bary maintains 

 that whatever may be the points of agreement between the 

 Monadinece and the Mycetozoa they are not such as to warrant 

 their being classed with the latter division as defined by himself.J 

 Lankester accepts the group as defined by de Bary, and places 

 them in his grade Gynmomyxa of Protozoa; he suggests their 

 affinity with the Sporozoa.% 



The ingestion of bacteria by the swarm-cells appears to 

 strengthen the view that the group is more nearly associated 

 with the lower forms of animal than of vegetable life, and 

 the name of Mycetozoa appears to mark its true position in the 

 borderland between the two kingdoms. For a more complete 

 discussion of this subject I must refer to those who have paid 

 special attention to the allied groups. 



In preparing this catalogue of the collection of Mycetozoa in 

 the British Museum, the arrangement of orders and genera given 

 by Eostafinski in his Monograph || has been mainly followed, 

 with such alterations as observations made during recent years 

 have rendered necessary. De Bary made the group the subject 

 of minute and thorough investigation ; IT and Eostafinski, while 

 studying under him at Strassburg, devised a system of classification 

 which is clear and comprehensive, and is now generally accepted. 



The division by Eostafinski of the main section Endosporece 

 into two parts, distinguished by the colour of the spores, has been 

 objected to as being artificial and wanting in universal applica- 

 tion, but the cases in which species ofier difficulty with regard to 

 their position under this scheme are few, and on the whole the 

 organisms range themselves under the separate heads in a re- 

 markably natural manner, while for determining the species 

 the plan is simple and convenient. 



* De Bary, I.e., p. 449. 

 + md., p. 446. 

 X Hid., p. 448. 



§ Zoological Articles, 1891, pp. 11, 26. 

 II Sluzowce (Mycetozoa) Monographia (Paris : 1875). 

 •|f Comp. Morph. and Biol. Fungi, Mycetozoa, etc., p. 421. 



2 



