52 Proceedings of Royal Society of Edinburgh. [sess. 
phosphorus in the muscle of the salmon is 0215 per cent., and 
that of this about 0109 is soluble in water. 
To determine how much of this is in organic combination and 
how much in such compounds as phosphocarnic acid, the following 
observations were made : — 
1. 100 grm. of the flesh of a fresh sea salmon in March 1899 
were extracted repeatedly with over 2 litres of water and acetic 
acid. The watery extract was boiled and the precipitate well 
washed. The inorganic phosphorus was precipitated with ammonia 
and chloride of calcium. In the precipitate the phosphorus was 
estimated in the usual way, calcium being washed out of the 
molybdate precipitate with 10 per cent, nitrate of ammonia 
solution. 
Mg 2 P 2 0 7 = '357, P 2 0 5 = -228, P=-099 
The filtrate containing any phosphocarnic acid was evaporated, 
burned and treated with molybdate of ammonia, and P. estimated 
as above. 
Mg 2 P 2 O 7 =-017, P 2 O 6 = *011, P = 0-005 
2. 135 grm. of the flesh of a kelt (32) captured in March, was 
analysed in same way : — 
Mg 2 P 2 O 7 =-330, P 2 0 5 =-211, P 2 0 5 %=156, P = 0-068% 
The filtrate, containing any phosphocarnic treated as above, gave 
no precipitate with ammonia-magnesia mixture. 
The phosphorus extracted by water from the muscle is almost 
entirely in simple inorganic combination. 
The evidence thus supports the view that the ovarian ichthulin 
and the testicular nuclein are built up from simple inorganic 
phosphorus compounds derived from the muscle. 
D. Further Observations on the Source of the Pigment 
of Salmon Muscle. 
By M. I. Newbigin, D.Sc. 
On the Pigments of certain Crustacea. 
It is well known that the salmon when in the sea feeds largely 
on herring, and that these in turn prey upon small free swimming 
Crustacea, many of which have a bright red colour. It therefore 
