SAPROLEGNIA 59 



seen it was so like 5. mofioica tliat it was possibly identical with it; I)ut 

 it might also be a distinct form ciuite without oogonia, somewhat like 

 (in this respect) Leptomittis lactetis. Hine's ('78) figures and descrip- 

 tion indicate the present species (pis. 4-5), particularly in the prolifera- 

 tion of sporangia at times by lateral growth from below, as in Achlya 

 (p. 95). He records the natural infection of uninjured tritons {Mino- 

 branchus) in an aquarium at Cornell University and also experimental 

 infections of injured animals which died in about three or four days. 

 Dictiosporangia were also obser\-ed; but no sexual reproduction. As 

 to remedies Hine notes the curing by Mr. Gage of an eel by sponging 

 it wth a ten per cent solution of carbolic acid, and of MinobrancJius 

 by sponging with camphorated water. He also quotes from Rev. M. J. 

 Berkeley, who says in his Treasury of Botany that carbonate of soda, 

 and probaI)ly also bisulphate of potash, will prevent the growth of these 

 parasites. 



The sterile species described by Lindstedt in his Synopsis (p. 48) 

 may possibly be this, but is more probably a very sterile strain of S. 

 didiua, as he obtained it on flies from water in which had grown Chara, 

 and the drawings look more like the latter species. 



Radais (1898) found a sterile Saprolegnia in a conduit and referred it 

 with some doubt to S. ferax, which it could hardly be. 



Tempere (1904) calls a parasite on fish that he found 5. ferax, al- 

 though oogonia were not observed. It was probably S. parasitica. 



Hardy (191 1) found a sterile Saprolegnia infecting several species 

 of j'oung trout and associated with the alga Myxonema, the latter with 

 branched filaments about i cm. long and, apparently, more conspicuous 

 than the fungus. The fungus was always present with the alga, but 

 itself occurred alone at times. Hardy had previously noted this alga on 

 goldfish and incidentally mentioned the presence of a fungus (1907), 

 and Minakata had found this alga on fish in Japan, but did not men- 

 tion a fungus associate (Nature 79: 99. 1908). 



Miss Collins (1920) describes considerable variations in behavior of 

 the sporangia and spores in a sterile species found by her in South Aus- 

 tralia. It may be the same as ours. 



Huxley (1882) has shown that the Saprolegnia he studied could 

 advance into sound tissue from infected areas and was thus capable 

 of being a parasite. It is of course not an obligate parasite, and Hardy 

 (1. c.) suggests that its attacks on fish may be prepared for by parasitic 

 bacteria such as Bacillus salmonis pestis or B. piscicidus bipolaris. 



To test for length of life a pure culture was put in a jar of distilled water in March, 

 I917. Grubs placed in contact with this culture se\eral limes between Sept. 14 and 25, 

 1917, failed to show growth. 



