PARTULA OTAHEITANA. 243 
THE MENDELIAN INHERITANCE OF THE COLOR-PATTERNS. 
The variety sinistrorsa exhibits two primary forms of coloration in nearly every 
valley of its occurrence, namely, the plain and the banded; as in the case of affinis, 
therefore, an opportunity is presented for an inquiry into the phenomena of heredity, 
to ascertain whether these two forms are Mendelian alternatives in nature and 
behavior. It is true that the unbanded classes named apex and phea are not alike 
in details, but they form a single group in contrast with the cestata class, for the 
purposes of the inquiry. 
For one reason or another, the available material is reduced to the colonial 
statistics of four valleys, namely, Tenaire, Maara, Faarahi, and Moaroa. ‘The 
Titaviri data are useless because there is no record of even a single banded shell 
among the young; in Vaipoe, on the contrary, all of the young of cestata are banded. 
Too often the striped class is so poorly represented in both the adult population 
and the embryonic series as to make an analysis fruitless or impossible. Four 
independent valley series remain, and their analysis must possess some degree of 
positive value, especially because the two characters under consideration are pre- 
cisely the same as in the case of afinis. Furthermore, in Tenaire and Maara there 
are two kinds of plain shells, as well as dextral representatives of all classes, whereas 
in Faarahi and Moaroa the material includes only sinistral phea and cestata; hence 
there is sufficient diversity of material to render the general consistency of the 
results obtained all the more significant. 
TENAIRE VALLEY. 
As stated above, the material in this case is complex, but fortunately it is 
abundant. The fundamental data relating to the numerical proportions of the 
two classes in the population are as follows: 
Plain. Banded. 
Whole population 674/907 =74.1 p. ct. 233 /907 =25.8 p. ct. 
Sinistral 265 /374 =70.8 p. ct. 109 /374 =29.1 p. ct. 
Dextral 409 /533 =76.7 p. ct. 124/533 =23.2 p. ct. 
Gravid parents with distinguishable young are classified as follows: 
In the absence of certainty as to the interbreeding of sinistral and dextral snails, 
the analysis of the whole combined series is less useful than that of either component 
group taken by itself; but, nevertheless, the former has a value not only because 
larger figures are available, but also because natural errors in one series would tend 
