I 6 HUMPHREY 



injury. The infection spreads from plant to plant quite rapidly. 

 In a dinner-plate full of material, at first the majority of plants 

 examined were unaccompanied by fungus, but within three 

 weeks, on one side of the plate all the plants were turning brown ; 

 on examining these they were found to be infected. The fun- 

 gus seems usually to make its attack through the ventral side 

 of the thallus, though occasionally a plant would be found with 

 hyphas on both sides. Microtome sections failed to reveal any 

 vesicular structures within the host. 



Anetira, being naturally less compact and vigorous than such 

 forms as Fegatalla or Lwiularia, furnishes a poorer field for a 

 parasitic fungus and seems less able to cope with the fungus. 

 This, however, may be partly due to greater vigor of the par- 

 asite. It must also be noted that infected plants behave dif- 

 ferently under varying conditions. Aneitra tnultifida major 

 as we find it here is semi-aquatic as to habitat and when grow- 

 ing under perfectly normal conditions may be considerably in- 

 fected without showing any effect other than becoming yellow- 

 ish green in color. If, however, these same plants are brought 

 into the laboratory, even though well supplied with moisture, 

 under a bell-jar they become brown in color finally dying, 

 while uninfected plants seem to thrive quite as well as when 

 growing out-of-doors under normal conditions. Plants grow- 

 ing along streams, though receiving little less than the required 

 amount of water, if infected, seem less able to throw off the 

 effects of the fungus than plants growing under perfectly 

 normal conditions of moisture, light, etc. 



Aside from the fungi found in association with Fossombronia, 

 Fimhj-iaria and Aneura, the writer has had occasion to study 

 infected material of Anthoceros ^earsoni and Porella holanderi. 

 In habit of growth the fungus associated with Anthoco'os is 

 very much like that infecting Aneura though none of the 

 material examined showed any structures suggestive of fruiting 

 organs other than conidia which were being formed in consid- 

 erable numbers by abstriction along the external hyphjE. They 

 branch freely and are seen to anastomose not at single points 

 here and there but continuously for some length, both hyphae 

 being rather minutely septate along the length of contact. The 



