PHYSIOLOGY AND MORPHOLOGY OF CALIFORNIA HEPATIC/E 45 



having dried thirty-two days. Between 20 and 25 per cent, 

 of these spores failed to recover. The last lot of spores were 

 sown on March 3 — fifty-two days after collecting. Approxi- 

 mately forty per cent, of these were desiccated beyond recovery. 

 Time does not permit at the present further testing of the spores 

 of this species but judging from the results of the above cultures 

 very few if any spores could endure longer than a few months 

 at the most. 



Porella bolanderiv^z.?, then experimented with, cultures being 

 started at various intervals using the same media as in preced- 

 ing cultures. The results obtained were not greatly different 

 from those in the case of Radiila though in my last culture 

 which was made on March 5 not more than half the spores have 

 recovered and fewer still have germinated after eleven days. 

 The spores in this culture had been allowed to dry thirty-eight 

 days, or fourteen days less than was allowed spores used in the 

 last Radula culture. Making due allowance for the possibility 

 of toxic effects due to the activity of bacteria or fungi that might 

 have been in the various cultures it is highly improbable that 

 the failure of constantly increasing numbers of spores to revive 

 could have been entirely due to any such cause and we are jus- 

 tified in the conclusion that the spores of these forms and prob- 

 ably some others not yet investigated are incapable of enduring 

 more than a comparatively slight amount of desiccation. 



Summary. 



1. Plants of Fossomhronia longiscta, as it occurs here, are 

 seldom free from infection by a fungus, which, in its relation 

 to the host, acts as a true parasite. In early stages the fungus 

 is confined to the rhizoids and compact tissue of the stem, ulti- 

 mately extending throughout all vegetative tissues of the gameto- 

 phyte. Large, black sclerotia develop within the cells of the 

 leaves and peripheral cells of the stem, resulting in the death 

 of the host. 



No instance of infection of sex organs or sporogonium has 

 been observed. 



2. Fimbriaria calif ornica has been found to"be infected by 

 a fungus, the hyphee being confined to the outermost three or 



