54 Ovaries of the Gar, Lepidosteus 



of the muscle at first increase slightly, then remain comparatively 

 constant in proportion to the tissue waters until late in the spawn- 

 ing. At the spawning when the animals are approaching death 

 by inanition the tissue waters are less saturated. In the devel- 

 oping ovaries the organic extractives are of a much lower con- 

 centration than in the muscles. The percentage does not vary 

 much during the entire migration. C. H. Greene (1919) found 

 with respect to the muscular tissue that while the absolute amount 

 of protein decreases, the organic extractives, especially the amino 

 nitrogen, remain constant or increase in spite of the fact that the 

 protein from which they are derived is constantly decreasing. 

 The lower concentration in the ovaries would seem to be a func- 

 tion of the anabolic processes whereby the ovarian extractives 

 are being synthesized into proteins. At any rate the gar muscle 

 extractives average about 2.5 per cent while the extractives of 

 the ovaries average about 1 per cent. 



If the ratio of organic extractives to protein be figured for the 

 series given in Table II, it will be seen that the extractives exist 

 in the largest ratio in the youngest ovary, Cll (Table III). In 

 C20, which contained a large number of small immature ova, the 

 ratio is also 1 : 10. In 42a, which was certainly the oldest 

 specimen, the ratio is the smallest, 1 : 52. The other ratios vary 

 in no regular order from 1 : 24 to 1 : 42. In the case of the amino 

 nitrogen, the amounts are again certainly greatest in the young- 

 est specimens, decreasing with maturity. 



In general there is a good deal of variation in the figures for the 

 fractions of the organic extractives; viz., total nitrogen, amino 

 nitrogen, and creatine. In view of the relation between amino 

 nitrogen recently pointed out by C. H. Greene (1919) it is of 

 interest to note that the sample having the highest water content, 

 Cll, has also the highest value for amino nitrogen, and that the 

 one with the lowest water, 42a, gave with one exception the lowest 

 value for amino nitrogen. The low value for C36 is not explained. 



Konig and Grossfeld (1913) have studied the composition 

 of the extractives of fish eggs, and have isolated xanthine, hypo- 

 xanthme, creatinine, taurine, and tyrosine. In view of the ease 

 with which creatine is changed to creatinine in the manipulations 

 of the analysis, Grindley and Woods (1906), it would seem doubt- 

 ful whether there is really any preformed creatinine in fish eggs. 



