FUNGI CONTINUED: CLASSIFICATION. 



215 



ant 



o o 



blight (Phytophthora), the white rust of cruciferous plants (Cystopus = 

 Albugo), the damping-off fungus (Pythium), and many parasites of the 

 algae known as chytrids, as Olpidium, Rhizophidium, Lagenidium, Chytri- 

 dium, etc. 



The two following orders are sometimes placed in a separate subclass, 

 Archimycetes. 



433. Order Chytridiales (Chytridineae). These include the lowest fungi. 

 Many of them are parasitic on algae and lack mycelium, the swarm spore 

 either with or without minute rhizoids, developing into a globose sporan- 

 gium (Rhizophidium, Chytridium, Olpidium, etc., fig. 249), or the swarm 

 spore attached to the wall of the host develops into a long sword -shaped 

 body with a sterile base, which proliferates 



and forms a new sporangium in the old one 

 (Harpochytrium), or with slight develop- 

 ment of mycelium in aquatic plants (Cla- 

 dochytrium). Some are parasitic in leaves 

 and stems of land plants. Synchytrium 

 decipiens is very common on the trailing 

 legume, Amphicarpaea monoica. 



434. Order Ancjlistales (Ancylistineae). 

 The members of this order have a slight 

 development of mycelium and many are 

 parasitic in algae (Lagenidium, fig. 249). 



435. Order Saprolegniales (Saproleg- 

 niineae). These include the water molds 

 (Saprolegnia). See Chapter XIX. 



436. Order Monoblepharidales (Mono- 

 blepharidinese). These are peculiar water 

 molds, related to the Saprolegniales, but 

 motile sperm cells are formed (Monoble- 

 pharis, etc., fig. 250). 



437. Order Peronosporales (Peronospori- 

 neae). These include the downy mildews 

 (Peronospora, Plasmopara, Phytopthora, 

 etc.), and the white rust of crucifers and 

 other plants (Cystopus= Albugo), Chapter XIX. 



2. SUBCLASS ZYGOMYCETES. 



438. These are the conjugating fungi. 



439. Older Mucorales (Mucorinese). This includes the black mold and 

 its many relatives (Mucor, Rhizopus, etc.). Chapter XIX. 



440. Order Entomophthorales (Entomophthorineae). This order in- 

 cludes the "fly fungus" (Empusa) and its many relatives parasitic on insects. 



Fig. 250. 



Monoblepharis insignis Thax- 

 ter. End of hypha bearing oogo- 

 nium (oog) and antheridium (ant) 

 Sperms escaping from antheridium 

 and creeping up on the oogonium. 

 (After Thaxter.) 



