On the Transmission of Hereditary Characters. 467 



LVIII. — A Criticism of a Moderti Hypothesis of the Trans- 

 mission of Hereditary Characters. By E.. S. BerGH, of 

 Copenhagen *. 



In the following pages it will be my endeavour to refute an 

 hypothesis which has been disseminated exceedingly widely 

 during the last six or seven years and is often designated as 

 the " Theory of Heredity." 1 am unfortunately at present 

 unable to advance the subject by new observations of my 

 own, and still less can I introduce a fresh hypothesis by way 

 of compensation. Nevertheless this essay will not be alto- 

 gether useless, since the hypothesis in question is nowadays 

 supported by the most distinguished investigators and is even 

 represented in text-books as a proved reality, and because 

 the arguments upon which it is based^ in spite of the con- 

 spicuous importance of the matter, are nowhere discussed in 

 detail from the opposition side. I have for a long time been 

 an opponent of this hypothesis by reason of previous know- 

 ledge; thus in my lectures upon general embryology f I have 

 already represented this matter from another point of view, 

 and 1 took up a position still more decisively opposed to the 

 theory in my addresses upon General Histology |. And now 

 an investigator, whose knowledge of the processes of fertili- 

 zation entitles him to the highest consideration, has this year 

 published a paper § which shows in the clearest manner that 

 the theory alluded to was built upon sand. 



The hypothesis which we have to discuss may be summed 

 up in a very few words : it really consists only in the suppo- 

 sition that the nucleus (or, as certain authors imagine, the 

 chromatin itself) is the sole substance which has a part to 

 play in the transmission of hereditary characters, and that 

 consequently the cell-substance, or whatever lies outside the 

 nucleus, is of no importance in the connexion named. Among 

 the very numerous representatives of this doctrine let us here 

 mention only a few of the most important : — 0. Hertwig || 



* Translated from tlio ' Zoolo^isclier Auzeiger,' xv. Jahrg., uo. 383 

 (Feb. 1, 1892), pp. 43-52. 



t These appeared in print iu February 1887. 



X In the autumn of 1889 ; not yet published. 



§ II. Fol, " Die Centreuquadrille, eiue ueue Episode aus der Befrucht- 

 ungsgeschichto," Anatomischer Anzeiger, Jahrg., 1891, uos. 9, 10. 



II O. Hertwig, " Das Problem der lijfruchtuug uiid die Isotropio das 

 Eies, eine Theorie der Vererbung," Jeuaiscbe Zeitscbr. N. F., i 1 Bd., 

 1884. 



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