PARTULA OTAHEITANA. 295 
When these figures are combined, the anticipated numbers are: 
(5) Plain adults: plain young only, 44; both types, 82=126 
As compared with (4) above, there is a difference of 7, or 4.8 per cent of the 
whole number. The agreement is so close as to support the view that a Mendelian 
order of inheritance is followed in the history of the banded and bandless characters. 
When the factor for the plain pattern is assumed to be the recessive member of 
a Mendelian pair, the three gametic classes come out in the unsatisfactory propor- 
tions of I : 1 :4, which would not give a relatively stable colonial condition; this 
offsets the fact that the difference between expectation and observation in the test 
of the numerical relations amounts to only 3.8 per cent. 
SUMMARY AND CONCLUSION. 
The variety of Partula otaheitana called lignaria, which inhabits Tipaerui 
Valley, is well separated from the forms occupying the neighboring valleys on either 
side, namely, Fautaua and Taapuna, in correspondence with its topographical dis- 
continuity. In general terms, it differs qualitatively from the Fautaua association, 
(1) in the great preponderance of dextral members, (2) in the characteristic striga- 
tions displayed by almost all of the members, (3) by an abundance of banded 
components, and (4) by the absence of the red color-factor except in a small number 
of its upland population. It is distinguished from the Taapuna Valley association 
to the southwest, (1) by its dominant dextral coil, (2) by its strigated pattern, (3) 
by the large number of striped members, and (4) by the general absence of the red- 
dish or yellowish ground-color. 
Quantitatively, the /ignaria variety differs from the colonies on either side as 
indicated below (table 250), the facts being self-evident from the figures. A notable 
point is the astounding difference in all respects between the apertures of lignaria 
and crassa aberrans; in the matter of proportions, the difference is more than 30 
times the probable error. 
TaBLe 250.—Partula otaheitana lignaria dextral in comparison with Partula otaheitana 
otaheitana dextral and Partula otaheitana crassa aberrans sinistral. 
As compared with | As compared with 
Character. P. o. otaheitana, | P.o. crassa aberrans, 
Fautaua. Taapuna. 
Shelltlensth ym m ye ons earlier ict een risen eases —1.3229+ .0353 | [—0.0668=+ .0453] 
Wid Chey mney fiers Skene ai ete sala eRe ne eee — .5115+ .0194 {[— .0123+ .0219] 
FORROYOOAOMNG), [OEP CHMbococccccavo0caxn0ccdcv00000 +1.3310+ .0884 | [+ .1693+ .1101] 
INDENT ISOGIN, WM 500 con00d0cococ oR DDGGHODOADDDE — .4149+ .0188 — .1940+ .0227 
wid Cham Mb pecs rs peusreveioisleiee trcaaeue sent eiehecstere — .2228+ .0151 + .2918+ .0189 
PLOPOLLonS wpe Cen Une cei +1.1149+ .1097 +4.7335+ .1406 
Length aperture + length shell, proportions, per cent...| +1.4125+ .0768 — .8831+ .0926 
Mooth <p ery. sis sec eee shaders srelstens sans aca arcs + .5817+ .0338 + .9183= .0458 
