( 305 ) 



through the forming: of small epitheliinn pln,2:.s, irmwiiio' downwards 

 from the surface. 



And wliile the whole uterus is tryiuf;' to regain its normal shape 

 Iw means of contraction of all ils nuiscles throug-hont, the mucous 

 ni('nd)i'aiie must of course shrink considerahly ; Ihis |>r()cess follows 

 new lines, different from those which 1 have so far met with in any 

 of the puerperal uteri of mammalia, hitherto examined. 



How this involution process pj'Ogresses will be descrihed in details 

 by ])i'. W. KiHZ in an exhaustixe woi-k, freely enriched willi illu- 

 strations, and in which due attention is paid to the works of reference 

 w^ritten on the subject. 



... . f-*("0 



Mathematics. — ''Series tlcrircd from Ike series 2£ ." By Prof. 



w 



J. C. Kluyver. 



Hy [({in) we denote an arithmetical function of the integer in, 

 which equals if in, be divisil)Ie by a square, and otherwise equals 

 -|-J or — 1, according as in is a product of an even or of an odd 

 inunber of prime numbers. 



The series 



n{m) 1111 111 



m 2 3 5 6 20 20 30 ' " ' ' 



was considered by Eli.kk, \\ ho concluded that il converged towards 

 0, a theorem oidy recently proM'd by von Mangoldt (J 807) and 

 by Landau (1899). 



In this paper it will be shewn that in innumerable ways we may 

 select from Euler's series infinite groups of terms, each of these 

 groups again constituting a convergent series. 



In fact we may assume a linear congruence 



,c _ Ji {mod . h) 



an<l from Euler's series rehiin only those lei-nis the deiioniinalors 

 of which are solutions of the congruence. 



Fi-om 



'/' X"^ ''('"^ 



' 1,0 = 7 



we get thus the new^ series 



li{mh-\-h) 



T,L = V 



ijji 





