SOME NOVA SCOTIAN AQUATIC FUNGI. MOORE. 221 



complete for certain determinations. This paper will, at least, 

 serve to direct the attention ot" our botanists to the group which 

 will, no doubt, be found to be well represented in our flora. 



Family, S.-\PROLEGNIACE.-E. 



In this family the generic divisions are based upon the 

 characteristics of the sporangia and zoospores ; the specific divi- 

 sions upon the characteristics of the sexual organs. The three 

 genera which have appeared in the cultures made are Sapro- 

 legn'a, Achlya and Aphanomyces. 



In the first, the zoospores escape from the sporangium by a 

 common mouth and swarm separately. The sporangia are, as a 

 rule, renewed by the filament continuing its growth up through 

 the empty sporangium. A second sporangium may be cut off 

 before the tip reaches the top of the old sporangium and thus 

 several empty sporangia may be found one within the other 

 (fig. 1). In a few cases, the innovation of sporangia is hy 

 cyraose branching. 



In the genus Achlya the zoospores, on escaping from the 

 sporangium, collect to form a hollow sphere at its mouth and 

 there encyst (Fig. 16). The sporangia are renewed by the 

 filament containing its growth by a lateral branch arising at the 

 base of the old sporangium (Figs. 10 & 16). In both of the 

 preceding genera the swarm spores are produced in an indefinite 

 number of rows in the sporangia. 



In Aphanomyces, the zoospores are produced in a single 

 row, and after escape encyst at the mouth of the sporangium in 

 the same manner as in the genus Achlya. In this genus, too, 

 the rule is that but one oospore is produced in an oogonium, 

 while in Saprolegnia and Achlya the number is generally in- 

 definite within certain limits. 



