158 Kafirin 
Cuart 3. All these animals received a ration containing 15 per cent kafirin,! and 
lysine. Three of them, Rats 259, 260, and 261, received in addition tryptophane and 
cystine at the point shown by a. At point b, the cystine feeding was discontinued 
and thereafter these rats received as amino-acid supplements only lysine and trypto- 
phane. The other three animals, Rats 219, 233, and 265, received cystine in addition 
to the lysine at all times. 
The effects of cystine feeding are not marked, but the lot receiving this amino- 
acid made a distinctly greater gain than the other. The males normally grow faster 
than the females,-yet Rat 260 on the tryptophane ration, a male, grew somewhat 
more slowly than either of the females receiving the cystine diet. For a short time, 
the tryptophane lot received cystine, and it seems significant that in this brief period 
they should exhibit such a marked increase in the rate of growth. If the cystine 
feeding had been omitted, it seems probable that these rats would have made a still 
more unfavorable showing as compared with the cystine lot. 
