308 



SCIENCE 



[N. S. Vol. XLI. No. 1052 



from processes which were wholly complex 

 and dependent upon an association of 

 organisms? These intimate interrelations 

 of microorganisms have in a degree been 

 overlooked or neglected because of their 

 complexity. 



Garre^ suggested that one organism may 

 prepare the food for another by changing 

 the medium upon which it may be growing. 

 It is true that this had been demonstrated 

 some years before, by Pasteur and others, 

 but had scarcely been approached in this 

 manner. Marshall Ward' added to the 

 knowledge of the world by his studies on 

 ginger beer. The results secured pene- 

 trated the heart of the matter and made the 

 suspicions and facts regarding associations 

 replete with a new meaning and value. The 

 Japanese "sake," or rice wine, furnished an 

 example of sequence which too extended 

 the horizon of the nature of fermentations. 

 The milk preparations, koumiss, kephir and 

 many others, did not yield readily to pure 

 culture treatment if gauged by the native 

 products, and accordingly forced the notion 

 of mixed cultures. 



Such findings in fermentations coupled 

 with ideas which had been advanced by 

 botanists, as Frank, gave to bacteriological 

 association deeper significance than had 

 been anticipated by the earlier workers. 

 Knowledge had progressed from loose asso- 

 ciational relationships through the morpho- 

 logical to the functional aspect of associa- 

 tion, as hinted by Garre. Now if func- 

 tional, as nutrition, is to be interpreted in 

 terms of physics and chemistry, then the 

 basis of attack is at once affirmed. Pf effer' 

 intimated some such foundation when he 

 advanced two classes, "Conjunctive Sym- 

 biosis," in which the functioning of one is 



4 Garrg, Korrespondenzol. f. Sohweis. Aerzte., 

 Bd. 17, 1887. 



5 Ward, PMlos. Trans., Vol. 50, 1892. 



6 PfefPer, Handbuch der Pflaneenphysiologie, 

 Leipzig, Bd. I., 1897. 



essential to the functioning of the other — 

 parasitism; and "Disjunctive Symbiosis," 

 in which there is more or less independence ; 

 nevertheless, this companionship may be 

 favorable or antagonistic. Out of these, 

 there have apparently emerged with some 

 definiteness "symbiosis," "metabiosis" and 

 ' ' antibiosis, ' ' terms familiar to every micro- 

 biologist, but not open to exact interpre- 

 tation. 



Pf effer 's classification provided an excel- 

 lent beginning for associational studies. 

 Whether the term "symbiosis" is satis- 

 factory in his classification depends largely 

 upon individual understanding. It has 

 seemed to me that "association" would be 

 better fitted for the place occupied by 

 "symbiosis," and the "symbiosis" be re- 

 served for a subclass in which a very inti- 

 mate interdependable relationship exists. 

 Apart from this, I shall follow the division 

 of Pfeffer in our discussion. 



In an effort to conform to these general 

 classes of Pfeffer 's, it is expedient to sub- 

 divide for detailed consideration, since the 

 idea of conjunctive association branches 

 into divers paths and disjunctive associa- 

 tion may include many loose relationships. 



Auto-relationships or those self-associa- 

 tions, as a class of conjunctive associations 

 which arise from growth and multiplication, 

 are peculiarly suggestive, for they are 

 commonly observed in the laboratory. 

 Organisms will flourish and grow within 

 limitations only upon an ordinary medium, 

 and in the natural changes as fermentations 

 and diseases occurring outside of the labo- 

 ratory, away from artificial influences, the 

 same phenomena are observable. Buchner^ 

 and Carnot^ have claimed that the cholera 

 bacillus and tubercle bacillus find more 

 favorable growth in cultures containing 



■^ Buclmer, Miinchen Arztl. IntelUgensbl., No. 

 50, 1885. 



8 Carnot, Comptes Med. Soc. de Siol., p. 765, 

 1898. 



