THE MYCETOZOA 59 



The spores, which at their formation are uninucleate (Fig. 1 8, c), 

 are found, on hatching, to contain four bodies which are apparently 

 nuclei (Fig. 18, d), so it would appear that division of the nucleus 

 occurs in the spore stage. When the spores are brought into 

 water the contents emerges, becomes amoeboid, and successively 

 constricted into separate lobes, two, four, and eight in number 

 (Fig. 18, e-ff). At the stage when eight lobes are formed each 

 develops a flagellum (Fig. 18, h), and finally, becoming distinct 

 from its fellows, swims off as a zoospore. It is evident that a 

 further division of the nuclei must occur during this process. The 

 zoospore subsequently enters the amoeboid stage, and the amoebae 

 probably fuse to form plasmodia, as in the Endosporeae, though the 

 process has not been followed in Ceratiomyxa. 



On comparing the somewhat incomplete details of this life- 

 history with those of the Endosporeae, it seems clear that the 

 abundant gelatinous substance in which the protoplasm is contained 

 at the end of the plasmodium stage of Ceratiomyxa is, as Famintzin 

 and Woronin pointed out, comparable with the secreted material 

 which is converted into the supporting structures of the 

 Endosporeae. In Ceratiomyxa the spores, instead of lying in a 

 compact mass, contained in a sporangium, are distributed in a 

 superficial layer, and the sporophore is accordingly disposed so as 

 to offer an extensive surface for their support. 



The division of nuclei prior to spore-formation, found wherever 

 the development has been followed in the Endosporeae, has not been 

 seen in Ceratiomyxa, and as this process is frequently met with in 

 other groups of Protozoa, its apparent absence here is remarkable. 

 It is possible that this division is represented by the first of the 

 nuclear divisions occurring within the spore ; in which case the 

 spores of Ceratiomyxa would be comparable with the masses into 

 which in the Endosporeae the protoplasm separates about the 

 dividing nuclei before spore-formation, rather than with the spores 

 of that group. If this comparison were established, however, the 

 two following divisions which occur in Ceratiomyxa before the 

 zoospores are formed would remain features peculiar to the genus. 1 



THE SOROPHORA. 



The other group here included with the Mycetozoa, the 

 Sorophora, consists of forms the alliance of which with the 

 Euplasmodida is somewhat remote. They live in decaying vege- 

 tables and the dung of herbivorous animals. There is no flagel- 

 late stage in the life-history, and it is in the form of amoebulae 

 that the active phase, with growth and reproduction by fission, 

 occurs. At the end of this vegetative phase, and only as a pre- 



1 Cf. the Postscript at the end of this article. 



