XV.] 



MOULD-FUNGI. 



147 



elongates and branches out. " The free ends of the stem-hyphae 

 rise above the surface of the epidermis and become converted 

 into zoosporangia, more or fewer of the spores of which attach 



Pxo. 106. SAPROLEGNIA OF SALMON DISEASE. 



A sporangium filled with zoospores : in connexion with them several youn- 

 mycelial threads. 



themselves to the surrounding epidermis and repeat the process 

 of penetration." In saprolegnia associated with the salmon- 

 disease Professor Huxley observed only the asexual mode of 

 fructification. 



L 2 



