BOOKS AND CURRENT LITERATURE 



Recent Results in Induced Mutations. — Students in genetics 

 are prone to distrust all evidence not discovered in their own labora- 

 tories and to view with suspicion all accounts of facts not amenable to 

 their o'vra favorite hj^potheses. No sooner does one cytologist base 

 conclusions of sex-inheritance upon the number and involutions of the 

 chromosomes than another counts them differently and fails to find the 

 odd one. Some would have the mutation theory stand or fall upon the 

 evidence obtained from the evening primroses and then, having driven 

 the matter into a corner, as it were, they proceed to make something 

 just as good as Oenothera Lamarckiana by hybridization, which never- 

 theless by some oversight in the synthesis fails to mutate. If one is 

 working with guinea pigs the inharmonious behavior of chickens in 

 another place is a grave matter; if birds are facile for breeding, beetles 

 for undefinable reasons are hardly eligible; if lizards are productive of 

 startling results, the decided action of crustaceans must surely have been 

 due to- unconscious selection on the part of the experimentahst; if you 

 have isolated genotypes of beans or wheat the derivatives of pomace 

 flies must be ascribed to heterozygotes; likewise the breaks in heredity 

 induced by tense emdronment or ovarial treatments must have been 

 due to masked genotypes; if you are a mutationist the alleged progress 

 of a selected series beyond a certain point was due to a discontinuous 

 variation, while if you are a selectionist or a statistician nothing matters 

 at all unless it is displayed by a thousand individuals in a hundred gen- 

 erations. 



It is a pleasure to turn from this medley of narrow cynicism to the 

 clear cut results of Miss Scieman^ who has been testing the action of 

 various excitation agents upon the common black mould, {Aspergillus 

 niger) in the laboratories of the Agricultural High School at Berlin. 



The mould was grown on agar containing a nutritive solution of cane 

 sugar, peptone, potassium phosphate, potassium nitrate, and magnesium 

 sulphate, and was subjected to the action of such substances as potas- 



' Scieman, E., Mutationen bei Aspergillus niger van Tieghem. Zeitschr. f. 

 ind. Abst. u. Vererbl. 8: pts. 1 and 2, 1912. 



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