S. H. HUTNER 



dition: the test of whether a particular metaboUc pathway is to 

 be studied in a protist or in the cells of a cellular plant or animal^ 

 is convenience. The careful morphological studies of the past are 

 invaluable in providing a wide choice of well-described species 

 for experimental use. The rapidly-expanding science of funda- 

 mental biochemical mechanisms, loosely termed "cell physiol- 

 ogy," is litde concerned with the devices— the hormones, and ner- 

 vous, circulatory, and excretory systems— coordinating the activi- 

 ties of the cells of cellular organism; it deals instead with the 

 autonomous activities of cells and non-cellular organisms. 



Biologists today are unable to explain satisfactorily the inner 

 mechanisms of such processes, to name but two, as photosynthesis 

 and neoplastic growth. Knowledge of both must be drawn from 

 the same fund of data on cell physiology. This is not to imply 

 that cancer is entirely a cellular process ; it is well-known that cer- 

 tain tumors are under a degree of hormonal control, e.g. tumors 

 aflfecting secondary sex characters. But all neoplasms have cellular 

 proliferation as their basis. To understand abnormal growth one 

 must understand normal growth. Photosynthesis is a vitally inter- 

 esting reaction not alone for its obvious economic significance as 

 the main generator of energy for life, but also because many of 

 the components of the photosynthetic apparatus are closely akin 

 to or identical with components of heterotrophic systems. The 

 solution of such complex problems as photosynthesis or cancer 

 is not to be achieved by an exclusively frontal attack. As pointed 

 out by Darlington (1948), the electric light was not invented 

 through attempts to improve candles. Every means of extending 

 knowledge of the cellular basis of growth must be called upon. 

 The algae allow an attractive simplicity in the design of experi- 

 ments on photosynthesis, nutrition, and genetics — all subjects 

 which contribute to the understanding of growth. 



It has been remarked by Dr. Bernard Davis that there are no 

 blind alleys in biochemistry. Recondite items of biochemistry 

 have a way of contributing to essential later developments. A 

 classical example is F. Gowland Hopkins' investigations of the 

 pigments of butterfly wings, which materially assisted the eluci- 

 dation of the structure of folic acid. This emphasizes that one 



