Beard, On the Occurrence of Dextro-rotatory Albumins in Organic Nature. | f> | 



mence with "The History of a Transient Nervous Apparatus" and 

 end in "The Enzyme Treatment of Cancer". 



To the investigator, groping slowly along an untrodden path, 

 it was of very great value, when, in 1907, it was recognised, that 

 the antithetic alternation of generations, which by observation had 

 been found to underlie the cycle of animal development, was in 

 reality based in the same antithesis of isomeric compounds of carbon 

 as that laid bare by the epoch-making researches of Pasteur. These, 

 as is well known, culminated in the foundation of a science of 

 stereochemistry. Since 1860 stereochemistry has been advanced 

 by the researches of many chemists, and here of these the names 

 of Le Bel, van't Hoff, Wislicenus, and Emil Fischer need 

 alone be mentioned. 



Modern Embryology, like modern Zoology in general, has con- 

 cerned itself little with Chemistry. As can be perceived now, many 

 questions, which have troubled embryologists and zoologists, might 

 have been settled easily once and for all and long ago, had the 

 contending investigators occupied themselves with the problem of 

 the true chemical nature of the animal under discussion, instead 

 of assuming, that, of necessity, all animals were alike in chemical 

 nature and composition. The embryology of Carl Ernst von Baer 

 and of his successors until recent times \vas exclusively a descrip- 

 tive science based in observation. There was, indeed, but a single 

 criterion, by which anything embryological could be determined, 

 and that was the fate of the cells concerned. But, since in any 

 developing "germ" the cells composing it are living, all questions 

 concerning their fate during development are bound up with 

 chemical, and indeed stereochemical, problems, which demand 

 answers. 



In 1906 it first dawned upon me, that in organic nature there 

 must exist at least two sorts of living albumins, laevo- and dextro- 

 rotatory respectively, and in 1907 the conclusion was published, 

 that the albumins of cancer and of malignant tumours in general 

 must be dextro-bodies, because of the destructive action, ending 

 in liquefaction, of active pancreatic ferments, especially trypsin, 

 upon them. Because of all this it became desirable to demonstrate, 

 and by some method above reproach, that dextro-rotatory albumins, 

 similar to those of cancer, did exist, and, indeed, were widely 

 present in other portions of organic nature. With this end in 

 view in the summer of 1912 I began a series of experiments, and 

 now record some of the results. The vastness of the fields of 

 animal development and of the unicellular animals or Protozoa 

 would, no doubt, permit of a wide series of experiments, but to 

 carry out very full series would require much time, material, and 

 financial means not at my disposal. 



