732 
Proceedings of the Royal Society 
is in some way either suitable or unsuitable for the propagation 
and growth of the fungus. Whether this arises from too high 
or too low condition, I am quite unable to say ; hut I may remark 
that while some of the fish examined were in the kelt stage, others 
were in a condition perfectly fit for food. 
Saprolegnia ferax parasitic on the Salmon. 
a. Barren filament, b. Prolific filament, c. Prolific filament, more highly 
magnified. 
4. On some New Bases of the Leucoline Series, Part I. 
By Gr. Carr Bobinson. 
5. On the Crystallisation of Isomorphous Salts. 
By G-. Carr Bobinson. 
It is generally stated that isomorphous salts are capable of crys- 
tallizing together in any proportions, or that the isomorphous 
elements which enter into them are capable of replacing one another 
in any proportion; e.g., potash alumina alum and potash iron 
alum can crystallise together in all proportions. 
