IV AUTHOE S PEEFAOE 



Parturition of the Cow ") ; Figs. 16 and 25 I owe to the kind- 

 ness of Messrs. Fricker and Frohner. 



As regards the balance, the work must speak for itself. In 

 conclusion, I thank all who so kindly aided me in the elabora- 

 tion and translation ; I also take this opportunity to express 

 my profound thanks to Prof. Dr, Frohner for revising the proof 

 sheets. 



M. G. DE BRUIN. 



Utrecht, May, 1897. 



