FEEDING HABITS 



49 



copiis, P. serpida, and P. virescens form 1 to 2 swarm cells. Each 

 swarm cell is amoeboid on emergence, but soon an anterior flagel- 

 lum develops. The swarmers fuse in pairs by apposition of their 

 posterior ends [Howard (1931)1, and nuclear fusion soon fol- 

 lows. As the Plasmodium increases in size, the fusion nucleus 

 repeatedly divides equationally and simultaneously. 



Fig. 11. Types of fructification among slime molds. Aethalium, as in 

 Fuligo septic a, the entire plasmodium becoming a sporocarp; plasmodio- 

 carp, as in Heitiitrichia serptda, plasmodium somewhat reticulate; sporangia, 

 as in most species, plasmodium becoming separated into groups of fructi- 

 fications. 



In Physannn poly cephahnn from 20 to 40 minutes is required 

 for the completion of mitosis [Howard (1932)]. There is lack 

 of accord concerning the exact point at which reduction division 

 occurs. It may take place just before cleavage of the plas- 

 modium into spores, or the spore may be diploid, in which case 

 3 of the 4 nuclei arising by meiosis within the spore may disinte- 

 grate. 



Feeding habits. The plasmodia ingest a variety of materials, 

 even those which are utterly useless as food. In nature they 



