l8o LAKES AND RIVERS, 



fecundation thus is performed by the entrance of an 

 antherozoid through the opening of the egg. The 

 antherozoids climb on the surface of the egg, until 

 finding the opening they enter and spread the viscous 

 matter of which they are composed on the surface of 

 the gonospheria. 



" This occupies a few minutes. Then the gono- 

 spheria by a slow movement encloses itself in the 

 egg and remains there about five minutes. The 

 fecundated mass is then formed into a ball environed 

 in a covering or skin which escapes through the 

 opening in the original egg. 



" M. Cornu has watched the whole process com- 

 pleted in about an hour. 



" He gives many minute details which we cannot 

 enter into, and describes the variations in the com- 

 portment of the two species he has specially watched. 



" He differs considerably in his deductions from 

 former botanists who have studied these difficult and 

 delicate species. 



" What are the causes of the ravages of this fungoid ? 

 I do not hesitate to say unwholesome water, produced 

 by river pollution, either by sewage, factory or mine 

 drainage, rendering it difficult for the higher organic 

 life to live, and facilitating the development of the 

 lower fungoid life. The wide dissemination of the 

 fungus on the salmon both in England. and on the 

 continent forbids us assigning any special impurity in 

 the water to its development, but clean rivers free 

 from decomposing dead fish and chemical washings 

 are the least liable to be affected. The water of every 

 river where the fish are found with this disease should 



