168 THE MYXOMYCETES OF PICTOU COUNTY. MOORE. 



retracted. Food material is apparently absorbed in solution, 

 but a series of observations recorded by Mr. Arthur Lister 

 (Linn. Journ. Botany, Vol. 25), establishes the fact that, in 

 some instances at least, living bacteria constitute no inconsider- 

 able portion of the food of the swarmers. His observations 

 were made on the swarm cells of Stemonitis fusca, Triclila 

 fragilis and Chondrio derma 'difforme. In all these cases, bac- 

 teria were seized and drawn into the body of the swarmer 

 by means of pseudopodia projected from the posterior end. 

 The ingested bacteria were stored in vacuoles where they were 

 gradually digested. The process completed, the vacuoles were 

 observed to rise to the surface of the swarmer as bubbles and 

 discharge their contents of refuse and undigested material. 



Preparatory to undergoing division the swarm cell with- 

 draws its nagellum and rounds off. The nucleus then divides 

 by karyokinesis, the two daughter cells develop flagella and the 

 swarmer form is resumed. 



The swarmers frequently pass into a resting condition, 

 rounding off and developing a thin wall. In this form they are 

 known as microcysts. After being dessicated and remoistened 

 tihe wall breaks open and the escaping contents resume the 

 swarmer form. 



In the fusion of the swarmers to form plasmodia the nuclei 

 do not appear to be involved, but these persist as the nuclei of 

 the plasmodium. 



The Plasmodium. The Myxomycetes exhibit two types of 

 plasmodia, the first forming a network of vein-like strands which 

 spreads over the surface of the substratum or within its larger 

 cavities ; the second is more watery in consistency and lives in 

 the interstices of decaying wood, from which it issues only for 

 fructification. The first type is characteristic of the PhysaracesG 

 and the plasmodiia of various members of this order have furn- 

 ished most of the material for the investigation of the mor- 

 phology and physiology of the living plasmodium. This consists 



