Biologisches Centralblatt, 



Unter Mitwirkung von 



Dr. K. Goefoel und Dr. E. Selenka 



Professoren in Miinchen, 

 herausgegeben vou 



Dr. J. Rosentlial 



Prof, der Physiologie in Erlangen. 



Vierundzwanzig Nummern bilden einen Band. Preis des Bandes 20 Mark. 

 Zu beziehen durch alle Buchbandlungen uiid Postanstalten. 



XXII. Band. 1. Januar 1902. Nr. 1. 



In ha It: Cunningham, Unisexual Inheritance. >I assart, Versuch einer Einteilung 

 der nicht-nervosen Reflexe. Reinke, Beraerkungen m 0. Biitschli's 

 n Mechanismus und Vitalismus". Brcdig, Anorganische Fermente. 



Unisexual Inheritance 



by 

 J. T. Cunningham, M. A. 



The chief question on which biologists are divided in opinion at 

 the present time is that of the inheritance of acquired characters. 

 Darwin himself believed in such inheritance, although he attributed 

 to it only a subordinate importance as a factor of evolution. It would 

 perhaps be generally admitted that the question is still open, that on 

 the one hand the hereditary transmission of such characters has not 

 been finally disproved, and on the other hand that there is not suffi- 

 cient satisfactory evidence to prove that it occurs. But nearly everyone 

 interested in evolution, in spite of this formal admission, is firmly con- 

 vinced on one side or the other. The followers of one school, are 

 scarcely willing to consider any arguments in favour of the affirmative 

 side in the absence of direct experimental verification, while the 

 heretics frequently make damaging attacks on the system of doctrine 

 by which the facts of evolution are supposed to be explained on the 

 principle of selection alone. 



The rejection by many evolutionists of one factor which Darwin 

 admitted is due chiefly to the influence of Weismaun's writings, and 

 Weismann's opposition to it was not founded on an inductive method 

 of investigation such as that employed by Darwin, but arose from 

 his able and persevering endeavours to formulate a detailed conception 

 of the process and mechanism of heredity. Finding no facts or data 

 on which to base a conception of the process by which a change in 

 parts or organs of the body could be transmitted to the germ cells in 

 the reproductive organs, Weismann started from the assumption that 

 XXII. I 



