98 Investigations on the Life-History 



length in the ovaries of upper-water fish is about double that in estuary 

 fish. The amount shows a small, though marked, increase from May 

 to August, and an increase of four and a half times in October and 

 November as compared with the earlier months. 



A balance between fat lo<t from the muscle and fat gained by the 

 ovaries shows the following results : 



(a) Balance to August. 



Muscle. 



Amount of Fat 



in grms. 



Average in Estuary, - May to August, - - 770 



in Upper Waters, - July and August, - - 478 



Loss, 



Average in Estuary, - - May to August, - 15 



in Upper Waters, July and August, - 46 



Gain, 31 



Of muscle fat there goes to ovaries, 31 grra. 



there is available for energy, - 261 grm. 



(6) Balance to November. 



Muscle. 



Average in Upper Waters, - October and November, 159 

 in Estuary, - May to August, - - 770 



Gain, - 611 



Ovaries. 



Average in Upper Waters, - October and November, 204 

 in Estuary, - May to August, - 15 



Loss, - 189 



Of muscle fat there goes to ovaries, - - 189 grm. 



there is available for energy, - 422 grm. 



It is thus manifest that the fat which the salmon has stored in its 

 muscles when it leaves the sea is not only amply sufficient to yield all the 

 fat required for the fats of the growing ovary, but also abundantly suffi- 

 cient to yield energy far an enormous amount of muscular work. When 

 the changes in the proteids of the muscle have been considered, the 

 part played by each of these in the evolution of energy will be dis- 



INTERNAL FAT. 

 (a) Fat of Pyloric Appendages. 



Not only has the salmon leaving the sea this store of fat in its 

 muscles but it has also fat stored in the abdominal cavity round the 

 intestine and in the liver. 



In the salmon the visceral fat is chiefly collected round the pyloric 

 appendages According to Miescher Ruesch (loc. cit.\ p. 179, by the 



