110 TRANSACTIONS AND TKOCEEDINGS OF THE [Sess. lsii. 



I am informed by Prof. J. W. H. Trail, of Aberdeen 

 University, that the Apodya is found in the river Don, 

 below certain paper works. 



G. Massee, of Kew Gardens, states in the "British Fungi" 

 (Phi/comycdcs and Ustilaginca) that the fungus is found 

 in ditches and rivers, attached to wood, aquatic plants, 

 etc., and that it is not uncommon. 



Prof. E. Warming, of Copenhagen University, says 

 (p. 108, " Systematic Botany," Engl, transl. by Prof. Potter), 

 that Lcptoriiitiis ladcus, Agardli, is frequent in the waste 

 matter from sugar factories. 



Since the fungus appears in streams which receive 

 organic discharges, it must be regarded as an index of such 

 discharges ; in other words, it is an index of pollution. 



Massee describes it (p. 129, op. cit.) as "forming 

 tassel-like waving tufts, attached at the base, dirty 

 white, and slimy ; filaments up to 5 cm. long, and 

 6-1 2yu, thick, constricted at intervals, dichotomously 

 branched, flaccid." 



My observations confirm all these characters, except the 

 thickness of the filaments and the nature of the branching. 

 The average thickness of the filaments is lO-lo/j,: the 

 young branches are about 5/a thick ; tlie older branches 

 just below the constrictions may be as thick as 30//., while 

 in one instance I found the width Ijclow the constriction to 

 be 40/i. 



The branching in every case is lateral, and not 

 dichotomous as stated by Massee, but the branches 

 ultimately become as vigorous as the parent shoots, and 

 simulate true dichotomy. 



"While the branches mostly arise singly, I have found 

 and figured opposite branches, which are rare. The ordinary 

 vegetative branches always arise immediately below the 

 constrictions, as shown in the photographs. 



Schenk, in his " Ilandbuch der Botanik," Band iv. fig. G2 

 p. 374, shows papilhe arising laterally from the middle of 

 the zoosporangia ; these are the papilhe by which the 

 germinated zoospores ultimately escape. 



Saccardo describes the fungus as follows : — " Hyphte 

 constricted at regular intervals, sparingly branched ; zoo- 

 sporangia formed from the terminal portions of the branches. 



