58 American Fisheries Society 



fish, inasmuch as the contents of the testes are of an 

 intense opaque white and no transference of red mate- 

 rial has apparently taken place from the muscles to those 

 organs at the breeding season. It is not true to say of 

 all red-fleshed salmon that the red color is associated 

 with the building-up process, or storing of reserve ma- 

 terials, preparatory to the spawning period. That would 

 not apply to white-fleshed salmon or trout, and does not 

 appear to apply to the male, even in the species with 

 deep red flesh. Undoubtedly the red oily matter, abun- 

 dant in the flesh, does pass to the ovaries of the female, 

 and the eggs are brilliantly tinted by these abundant red 

 globules in the yolk-matter. It is interesting to note that 

 red eggs and pale or white living eggs are familiar to 

 hatchery officers, the red eggs being the product of red- 

 fleshed fish, and the white or colorless eggs being the 

 product of pale-fleshed females. Pale eggs of white- 

 fleshed salmon and trout are almost as colorless as the 

 eggs of the whitefish. What an important point this is 

 in the work of fish culture. The red-fleshed fish are 

 universally preferred, yet we often breed from pale- 

 fleshed parents. The greatest care should be taken to take 

 eggs from females characterized by the highly-esteemed, 

 deep red tint in the flesh. 



Theoretical Explanation of Color. 



How does this red color arise? What is the explana- 

 tion of its presence ? I dealt with the question over twen- 

 ty years ago in a paper in the Annals of Natural His- 

 tory, the title being "The Presence of Oleaginous Spheres 

 in the Yolk of Teleostean Ova," and I claimed that the 

 color of the flesh was an hereditary trait, and I there 

 pointed out that, if Professor F. M. Balfour's view be 

 correct, that the ova of Teleosteans had ancestrally di- 

 minished in size, then the fluids, such as myosin, lecithin, 

 etc., contained in the vitelline globe of the egg, would 

 diminish also. If all the contents did not diminish 

 equally; but in some species, a phosphorized oily fluid, 

 like lecithin, did not decrease proportionately, droplets 



