39 



tion hundreds of instnictions were given for the correct preparation of 

 the various media. Of ten very unusual procedures had to be appUed ; 

 it is said that the only complaint which ever passed Kokee's Ups was : 

 "How exacting the Chief was again this morning"! 



The surface of the freshly prepared agar-plates was always dried 

 by Beijerinxk himself. For this operation the lower side of the dish 

 was gently heated with a small gas flame, and the dish then deposited 

 on the bench. The water vapour gradually condensed on the lower 

 side of the cover which was then removed and dried with a clean 

 handkerchief ! For the sake of sterilization the cover was flamed, and 

 again put on the dish. The plates, thus prepared, the culture flasks, and 

 the tubes, were then inoculated — in later years with a trembling hand 



— in a way expressive of devotion, as if it were a religious act. The 

 inoculated media were finally put in one or more incubators to which 



— of course — no other worker had access. 



The next day, or the day after, the cultures were examined, 

 were smelt, and — if possible — were even fingered. In special cases 

 Beijerinck went so far as tasting some of the cultures! 



Then the cultures were carefuUy examined, first with a pocket- 

 lens with low magnification, next by putting the plates themselves 

 under the microscope. Often the great scholar was seen sitting, till far 

 into the night, bent over his microscope, delighting in the creeping of 

 soil amoebae over the surface of the plates, or piercing with his eyes 

 into the virgin forest of some fungal colony. 



The solid media were often powdered with various compounds, 

 in order to obtain special growth effects, increase in luminescence, 

 etc. In other cases, drops of dilute acid or of alkali were put on the' 

 surface of the plates, and the effect thereof observed. Small pieces of 

 the plates were cut out, and subjected to various treatments. 



In a word, everything that could possibly be done with a culture 

 plate, was done with it ! 



Only after the inspection of the plate was quite finished were the 

 individual microbes studied in microscopical preparations, and one 

 could be certain that here too, no detail escaped Beijerinck's atten- 

 tion. 



It will be clear that such a procedure was extremely propitious for 

 the discovery of microbial variation ; and the corresponding inspection 

 of liquid culture media was favourable for a minute analysis of fer- 

 mentation, agglutination and similar phenomena. 



All these observations unchained in Beijerinck's mind a wild 

 current of thoughts, and he then would often give free play to his 

 fancy. In such a mood he often called for his assistents, who then 

 were regaled with an elaborate discourse over his bacteria; the bact- 

 eria almost were raised to the rank of human beings, as may be 

 judged from a pronouncement like : " You could not have done, what I 

 succeeded in doing this morning, for they (i.e., the bacteria) don't 

 knowyou!" 



