C. DOBELL 349 



really of this sort : but there is little ground for the foundation of such 

 a hypothesis. Many established facts appear to be flatly contradictory. 

 It should not be forgotten, however, that acquired heritable adaptations 

 of this sort are described not only among the Bacteria, but also among 

 the yeasts and other Fungi ; and the observations have been made by 

 many independent and competent workers. 



These few remarks by no means exhaust the significant inferences 

 to be drawn from the works which have been under consideration. But 

 it is hoped that they may serve to call more attention to certain facts 

 which have hitherto been left in the obscure by-ways of bacteriology. 

 It will be admitted, I think, that the outcome of the work fragmentarily 

 recorded in the foregoing pages will be not merely of interest, but 

 probably of very great importance, to every student of genetics. 



LITERATURE. 



1911. Baerthlein. "Ueber Mutationserscheinungen bei Bakterien." (Ber. ub. 

 v. Toff. d./r. Ver. f. Mikrohiol Dresden, in : C. B. Bakt. i. Abt (Ret) Vol L. 

 Beiheft, p. 128.) 



1912. . " Untersuchungen iiber Bact. coli mutabile." (C. B. Bakt. i. Abt. 



(Orig.) Vol. LXVL p. 21.) 



1912 A. . "Weitere Untersuchungen iiber Mutationserscheiuungen bei 



Bakterien." {Ber. ub. d. vi. Tag. d. fr. Ver. f. Mikrobiol. Berlin, in : C. B. 

 Bakt. L Abt. (Ref.) Vol i.iv. Beiheft.) 



1907. Barber, M. A. " On heredity in certain micro-organisms." {Kansas Univ. 

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1909. Bexecke, W. Review of the work of R. Miiller, published in iS'. B. physiol. 

 Ver. Kiel, 1909 : and in " Die Umschau," 1909. {Zeitsch. f. indttkt. Abstam- 

 mungs- u. Vererbungslehre, YoL n. p. 215.) 



1912. Bershardt, G. and Markoff, W. N. "Ueber Modifikationen bei Bak- 

 terien." (C B. Bakt. L Abt. (Orig.) VoL Lxv. p. 1.) 



1908. BcRK, A. " Mutation bei einem der Koligruppe verwandten Bakterium." 

 (Arch. f. Hyg. Vol. lxv. p. 235.) 



1910. BcRRi, R. "Ueber scheinbar plotzliche Neuerwerbung eines bestimmten 

 Garungsvermogens durch Bakterien der Coligruppe." (C. B. Bakt. n. Abt. 

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1910. and Andrejkw, P. " Vergleichende Untersuchung einiger Coli und 



Paratyphusstamme." {C. B. Bakt. L Abt. (Orig.) Vol. lvi. p. 217.) 



1909. and Duggeli. "Beitrag zur Systematik der Coli-aerc^nes-Gruppe, 



u. s. w." {C. B. Bakt. I. Abt. (Orig.) Vol. xlix. p. 145.) 



