September 7, 1917] 



SCIENCE 



239 



we find that lie has not been as cautious and 

 that he sees in Dr. Walcott's fossil bacteria 

 certain resemblances in appearance and struc- 

 ture to nitrogen-fiising bacteria from soil (by 

 contest the bacteria referred to appear to be 

 Azotohacter and related forms). He is not 

 dismayed by the fact that the metabolism of 

 marine, denitrifying, lime-depositing bacteria, 

 and that of the nitrogen-fixing bacteria in soil 

 ■which utilize both atmospheric nitrogen and 

 organic carbon, are in a sense opposed to each 

 other. Still less is he troubled by the very 

 great difference between the metabolism of 

 nitrogen-fixing bacteria and the autotrophic, 

 nitrifying bacteria like Nitrosococcus and 

 Nitrosomonas organisms which do not utilize 

 organic food and derive their nitrogen from 

 aromonium salts' instead of free nitrogen). 

 In fact, he apparently thinks of the nitrifying 

 and the nitrogen-fixing bacteria as essentially 

 identical, as apjiears in the following state- 

 ment (p. 292) : 



The great antiquity of even higher forms of bac- 

 teria feeding on atmospheric nitrogen is proved by 

 the discovery, announced by Walcott in 1913, of a 

 species of pre-Paleozoic fossil bacteria attributed 

 to "Micrococcus" but probably related rather to 

 the existing Nitrosococcus which derives its nitro- 

 gen from ammonium salts. 



The illogical nature of this statement may 

 be brought out by substituting groups more 

 familiar to paleontologists than are bacteria. 

 Thus we have: 



The great antiquity of Carnivores feeding on 

 flesh is proved by the discovery of a species of 

 pre-Paleozoic mammal attributed to Herbivores, 

 but probably related rather to Eodents who de- 

 rive their food largely from grain and nuts. 



!N'eedless to say that Dr. Osborn would be 

 the first to see the weakness in such a state- 

 ment. In reality this paraphrase does not 

 exaggerate the illogical nature of the origi- 

 nal statement, though it may appear to do so 

 to the layman unfamiliar with the fact that 

 great differences in these tiny organisms are 

 very frequently hidden behind superficial re- 

 semblences in appearance. 



The almost universal uniformity in proto- 

 plasmic structure of living species of bacteria 



and their universal possession of a definite 

 membrane which gives them definite form 

 will cause bacteriologists to wonder at the 

 statements on the following page of Dr. Os- 

 born's article where he says : 



The cell structure of the Algonkian and of the 

 recent Nitrosococcus bacteria is very primitive and 

 uniform in appearance, the protoplasm being naked 

 or unprotected. 



Any one who looks at the uniform black of 

 the fossil organisms in the microphotographs 

 given and who realizes that these are pictures 

 of fossils and not of living organisms will be 

 skeptical in regard to the evidence on which 

 this statement is based. 



Statements based on evidence of the sort 

 furnished which claim that the presence in the 

 Algonkian of nitrifying, denitrifying or nitro- 

 gen-fixing bacteria has been shown appear 

 like a pyramid of speculation supported on an 

 apex of fact. They have, however, already 

 misled a bacteriologist into an acceptance of 

 one of these claims, for I. J. Kligler'' says in a 

 recent paper (p. 166) : 



Finally Walcott's discovery of bacteria closely 

 resembling our nitrogen fixers of the soil is added 

 proof of the primitiveness of these microbes. 



It is because of the great interest of the 

 findings by Drew and Walcott, that this word 

 of warning has been uttered to protect science 

 from conclusions which others have drawn 

 from them. If this is not done there is 

 danger that the next time reference is made to 

 their work it will be in some textbook as a 

 positive statement that nitrifying, denitri- 

 fying or nitrogen-fixing bacteria, or all three, 

 have been shown to exist as far back as the 

 Algonkian. R. S. Breed 



N. Y. Agricultural Experiment Station, 

 Geneva, N. Y. 



man and the anthropoid 

 To THE Editor of Science: In the July 27 

 number of Science Prof. Mattoon M. Curtis 

 devotes a column and a half to a criticism of 

 the " common error " that man is a lineal 

 descendant of the anthropoid apes. " The ev- 

 ident implication," he tells us, " is that the 

 = Jour. Bad., 165-176, 1917. 



