BULLETIN OF THE UNITED STATES FISH COMMISSION. 433 



and Brefeld,* a great amount of accurate information respecting the 

 Saprolegniwhas been accumulated of late years. 



CHARACTERISTIC FORMS OF THE SPORANGIA AXU SPOKES OF SAPKOLEGNIA. 



I. — A zoosprangium full of nearly ripe, zoospores from the skin of a living diseased salmon. 



II. — An empty zoosporangium, through the center of which the hypha is growing in order to pro 

 duce a new zoosporanginm. From the fresh growth of Saprolegnia on the diseased jaw membrane of 

 a salmon, cut otl'and placed in water. 



III. — A dictiosporangium from salmon Sa2)rolegnia cultivated on a dead fly. The spores have 

 remained in the interior of the zoosporangium, and, after encasing themselves, have there germinated. 



IV. — Zoospores of salmon Saprolegnia, germinating in water. 



V. — An oo.sporangium of Sajyrolegnia fiom the pike, cultivated on a dead fly. The oosporangia of 

 the salmon fungus in all respects resemble this. 



Signification of the letters: hy, hypha; ?«j;;i, zoosporangium ; zspr, zoospore; oospn, oosporangium; 

 oospr, oospore; anth, antheridial filament ; an, anlheiidium. 



* Botanische Uutersuchungen. Heft IV, 1881, pp. 109. 110. 



Bull. U. S. F. C, 81 28 Aug. 8, 1 8 8S. 



