BIOCHEMISTRY 33 



shown that in the infection of timber with the wood-boring 

 Mollusc Teredo norvegica, which only takes place during the 

 free -swimming larval stage, the larvae move toward the wood 

 under a chemical attraction. An extract of wood caused a 

 remarkable aggregation of the larvae, and of a number of pure 

 substances tested the only one causing the aggregation to any 

 marked extent was malic acid. As he points out, it is scarcely 

 possible, in view of the natural conditions which prevail in the 

 sea, that the larvae are actually attracted to wood. Rather 

 would it appear that this positive chemotropism exerted by 

 some constituent of wood enables the larvae to recognise wood 

 when they come in contact with it. 



Proteins and Amino-acids. — Slowly but surely reliable in- 

 formation regarding the constituent molecules of the proteins 

 is being collected, Dakin (/. Biol. Chem., 1922, 50, 403) has 

 carefully examined the hydrolytic products of caseinogen after 

 tryptic digestion for the presence of hydroxy-aspartic acid, 

 described as having been found by Skraup, but without success. 

 The synthesis and separation of two inactive forms of the 

 hydroxy-aspartic acid described previously by Dakin (/, Biol. 

 Chem., 48, 273) has now been supplemented by the resolution 

 of these acids into their optically active forms (/. Biol. Chem., 

 1922, 50, 403). 



The nitrogen distribution of the proteins of the soya bean, 

 cotton-seed, and coconut have been examined by Friedemann 

 (/. Biol. Chem., 1922, 50, 17), whilst Jones, Finks and Gersdorff 

 (/. Biol. Chem., 1922, 50, 103) report the chemical study of the 

 proteins of the adsuki bean {Phaseoliis anjularis). From the 

 latter two globulins were separated which show a marked 

 difference in their sulphur and nitrogen contents and in their 

 nitrogen distribution as determined by the method of Van Slyke. 



The proteins of the muscle tissue of the rabbit, chicken, ox, 

 horse, sheep, and pig have been subjected to an examination 

 of their diamino-acid content by Rosedale {Biochem. J., 1922, 

 16, 27), On the whole the results are in agreement with the 

 recorded analysis for mammalian muscle proteins. The slight 

 differences to which the author draws attention are without 

 doubt largely due to the inaccuracies of the Van Slyke method 

 for the distribution of nitrogen in the diamino-acid fraction. 

 Apart from this, the red meats appear to show a higher lysine 

 content than the white meats. A very careful and valuable 

 re-examination of the value of gelatin as a foodstuff has been 

 made by Robison {Biochem. J., 1922, 16, iii), who has been 

 at great pains to consider^ and as far as possible correct, the 

 sources of error associated with metabolism experiments. He 

 made the study on himself, and during the experimental period 

 subsisted on a vigorously controlled dietary. 



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