FREE AMINO ACIDS IN ANIMAL TISSUE 301 
glycine and serine is characteristic of adult mammalian and reptilian heart. Gluta- 
mine was present in higher concentration in newborn and adult heart than in fetal 
heart. As in hearts of other mammalian species", glutamine, alanine, taurine and 

Figs. 73-75. Chromatograms of extracts of mouse heart (75 mg). Fig. 73: 16th-day fetus. Fig. 74: 
1-day old mouse. Fig. 75: adult mouse (6-months old). Leucines, 3; valine, 4: hydroxyproline 
5 5: 75 : : crop oo d 
7; threonine, 9; glutamine, 13; asparagine, 24. 
Figs. 76-79. Amino acid patterns of chick heart. Fig. 76: 14th-day embryo. Fig. 77: 16th-day 
embryo. Fig. 78: 17th-day embryo. Fig. 79: young hen. 
, 
References p. 348/349 
