50 COMPARATIVE MORPHOLOGY OF FUNGI 



33, 3) and goes through several nuclear divisions. These processes are 

 repeated (Fig. 33, 1). At maturity the turbinate cells have a crown of 

 filamentous structures which may be regarded as haustoria. The axis 

 of this tuft swells to a sac (Fig. 33, 5) into which the contents of the turbi- 

 nate cells migrate. There some of the nuclei enlarge markedly and per- 

 haps degenerate. The sac also bears a crown of those peculiar growths; 

 at maturity, its membrane thickens, the growths fall off, the sac becomes 

 a hypnospore and the whole mycelium disintegrates. At germination, 

 the content of the resting spores is divided into a variable number of 

 sporangia (up to 15 or more) which are liberated by regular slits in the 

 wall. There they form emission collars and liberate the uniflagellate 

 zoospores (Scott, 1920). 



As related species may be mentioned U. pulposa on leaves and stems 

 of Chenopodium sp., U. Trifolii on the epigaeous ports of Trifolium sp., 

 U. Ruebsameni on the roots of Rumex scutatus, U. Potteri (Bartlett, 1926) 

 on Lotus corniculatus and U. pluriannulatus (Jones and Drechsler, 1920) 

 on Sanicula Menziesii. 



