238 
Miscellanea 
and the correlation * between the non-use of the tooth-brush and the number of decayed teeth 
was found to be for the boys + "074 and for the girls — -074. The correlation if a two-row table 
is formed by grouping A and B together is for boys + -004, and for girls — -069. The correlation 
in any case is trifling and in the case of the girls is unfavourable to the tooth-brush. However 
necessary for cosmetic purposes, it would appear from these data to exert no influence in 
the prevention of decay. 
The probable error of these correlation coefficients is about -03. They practically amount 
therefore to no correlation, and if they do not indicate any beneficial influence, at any rate they 
do not point to any harmful effect of the tooth-brush at the ages of thirteen and fourteen. 
IV. Note on High Values of j8 x and jS 2 . 
By GEORG DUNCKER, Ph.D. 
Auf der Siidseeexpedition der Hamburgischen wissenschaftlichen Stiftung hatte ich 
Gelegenheit zu deu beiden folgcnden Zahlungen : 
(1) St Matthias, Riffinsel bei Ekaliu, 22. ix. 08. 
Armzahl von Astcrina exigua Lam. — w = 600. 
V 4 5 6 
/ 6 582 12 
(2) Neu Pomrnern, Matupi, 9. iv. 09. 
Armzahl von Archaster typicus M. & Tr. — m = 902. 
V 4 5 6 
/ 2 895 5 
Ihre Bestimmungswerthe sind 
1. Asterina 
2. Archaster 
M 
5-01000 
5-00333 
<T 
0-17292 
0-08803 
01 
1-76048 
4-76152 
ft 
33-12965 
128-47974 
«1 
50-26143 
182-94327 
K 2 
0-50934 
1-20114 
und die beschreibenden Kurven dementsprechend 
1. y =y 0 (cos 3) 2m e-"3- (Pearson, 1895). 
2. y=y n {x-a) qi x'^ (Pearson, 1901). 
Hamburg, 28. i. 10. 
* The method used was that of the two-rowed table suggested by Pearson, Biometrika, Vol. vn. 
p. 248. 
