Biochemistry and Evolution 55 



and in Area noae by Kutscher and Ackermann ( 19331) i . but was 

 wrongly identified as the isomeric trigonelline at the time. 



Distribution studies have in the past been one of the more popular 

 kinds of comparative biochemistry, but they have been too few and 

 too far between. Classical examples are those of Kutscher and Acker- 

 mann (1933a, 1936). As an illustrative example here we may review 

 work done on the distribution of the phosphagens, with which the 

 author has some personal acquaintance. 



Work in this field began with the discovery by Egglcton and Eggle- 

 ton (1928) that although creatine phosphate occurs widely in verte- 

 brate muscles, it is absent from those of invertebrates. Meyerhof 

 (1928) found that, among invertebrates, arginine phosphate replaces 

 the creatine compound. This pioneer work was soon followed up on 

 a much larger number of species by Needham, Needham, Baldwin, 

 and Yudkin ( 1932 ) and gave results which led them to believe that 

 they had important evidence concerning the origin of vertebrates. All 

 the invertebrates examined contained what appeared to be arginine 

 phosphate, with notable exceptions in certain echinoderms (later 

 confirmed by Baldwin and Needham, 1937). In certain echinoids both 

 phosphagens were found to coexist. The same results were found in a 

 hemichordate {Balanoglossus salmoneus) and it seemed that the 

 results fitted in with Bateson's theory of the origin of vertebrates, i.e.. 

 that they arose through an echinoderm-hemichordate route. 



In all this there was a certain element of fortune. If this work had 

 been done not at Roscoff but at Woods Hole, these conclusions could 

 not have been reached because the echinoid and hemichordate studied 

 later at Woods Hole by Baldwin and Yudkin (1950) proved to contain 

 only one phosphagen each — arginine phosphate in Arbacia pustulosa 

 and the creatine compound in Saccoglossus koualevskii. 



The work of Baldwin and Yudkin (1950 I was mainly devoted to a 

 study of the phosphagen of marine annelids and was prompted by 

 the somewhat atypical behavior of the presumptive arginine phos- 

 phate of certain annelids studied by Needham, Needham, Baldwin, and 

 Yudkin ( 1932 ) and by the work of Arnold and Luck ( 1933 ) , accord- 

 ing to whom several species of marine annelids contain no arginine 

 whatsoever. 



The presence of new phosphagens among the annelids was demon- 

 strated and it was shown that none of them is identical with arginine 

 phosphate. One of the new substances was tentatively identified as 

 creatine phosphate, but its positive identification only came later on 

 with the work of Roche and his colleagues ( Roche, Thoai, Garcia, and 



