12 THE LOWER FUNGI— PHYCOMYCETES 



Anastomosis of several individuals in this fashion results in 

 the formation of the characteristic net-Hke structure designated 

 by Zopf the net-plasmodium. The fusiform individuals possess 

 a limited degree of contractiUty, but retain their individuality. 

 They appear to ghde along the threads of the net, and are thus 

 Umited in their wanderings. During this period of activity 

 they feed, increase in size, and undergo repeated division. 

 In division the cell elongates, is constricted at the middle, and 

 is finally pulled apart into two new individuals held together by 

 a plasma strand. The research of Zopf on Lahyrinthula indi- 

 cated that food is obtained in solution rather than in the solid 

 condition. 



At the close of the vegetative period the wandering cells 

 collect into sessile or stalked masses, and pass into an encysted 

 state which may be termed the fructification. The individual 

 cells in Lahyrinthula assume definite walls and are termed spores. 

 The chemical composition of the wall is apparently unknown. In 

 Diplophrys a wall is absent, and the cell is called by Ohve 

 (1901) a pseudospore. After a period of rest, the organism 

 passes again into the vegetative phase, the spores in germination 

 freeing one to four of the fusiform cells provided with polar 

 pseudopodia. 



The Labyrinthuleae are far less well known than the Acrasieae. 

 The species of Lahyrinthula have been observed only by their 

 authors Cienkowski and Zopf, while those of Diplophrys have 

 been very inadequately studied. The position of the group in 

 the classification is extremely doubtful. Many zoologists 

 include it in the Protozoa. The type of cell division seems to 

 indicate a relationship with the Monadineae of that group. The 

 net-plasmodium has only a superficial resemblance to the true 

 Plasmodium of the Myxomycetes, and it is unlikely that the 

 Labyrinthuleae are more than remotely related to them. 



Fungi. — The essential characters of the other groups of the 

 Thallophyta having been indicated above, the field is now 

 cleared for a general consideration of the fungi. This must 

 of necessity be somewhat more brief than would seem from 

 certain points of view desirable. 



The fungi constitute by far the largest and most diverse 

 group of non-chlorophyll containing thallophytes. In general 

 they may be said to differ from other colorless forms in the 

 possession of the filamentous vegetative structure known as 



