Biologisches Centralblatt, 



Unter Mitwirkung von 



Dr. K. Goebel und Dr. E. Selenka 



Professoren in Miinchen, 

 herausgegeben von 



Dr. J. Rosentlial 



Prof, der Physiologic in Erlangen. 



Vierundzwanzig Numinern bildeu einen Band. Preis des Bandes 20 Mark. 

 Zu beziehon durch alle Buchhandlungen und Postanstalten. 



XXII. Band. 15. Januar 1902. Kfr. 2. 



I nh alt.: Clinniug'hain, Unisexual Inheritance (Schluss). Massart, Versuch einer 

 Einteilung der nicht-nervosen Reflexe (Fortsetzung). Reillke, Bemerkungen 

 zu O. Biitschli's n Mechanismus und Vitalismus" (Schluss). Zykoff, Das 

 pflanzliche Plankton der Wolga bei Saratow. v. Linden, Experimentelle 

 Untersuchungen iiber die Vererbung erworbener Eigenschaften. 



Unisexual Inheritance 



by 

 J. T. Cunningham, M. A. 



(Schluss.) 



It does not seem to me that much light is or can be, thrown on 

 the problem of sexual dimorphism by the statistical methods of in- 

 vestigation now so much in vogue among biologists. Professor Karl 

 Pearson, although not claiming to be a biologist himself, has taken 

 a leading part in the development of the mathematical treatment of 

 biological statistics. In his Grammar of Science 1 ) he gives an outline 

 of the science of biology from what he considers the physical point of 

 view, as distinguished from the metaphysical. His exposition may be 

 perfectly sound so far as it goes, but I have been unable to discover 

 in it any discussion of the phenomena of unisexual inheritance. In 

 considering inheritance in animals which reproduce sexually he states 

 that there are three chief forms, blended inheritance, exclusive inheri- 

 tance, and particulate inheritance. 



By exclusive inheritance he does not mean unisexual inheritance, 

 but merely the inheritance by an offspring of either sex, of any 

 character exclusively from one parent 2 ). In another place he con- 



1) The Grammar of Science, 2nd Edition : London, A. & C. Black, 1900. 



2) For example when a black mouse is paired with a white the offspring 

 may be all black, or all white, or piebald black and white, or of a uniform inter- 

 mediate colour. The first two cases are exclusive inheritance the third is 

 parziculate inheritance, the last blended inheritance. 



XXI. 3 



