PARTULA OTAHEITANA. I51I 
In brief, rubescens as a primary variety seems to have been derived from a 
complex basic stock like that still existing in Fautaua Valley, through an elimination 
or dropping out of certain qualities represented in the original heritage. 
The absolute and relative members of P. 0. rubescens in the valleys of its 
occurrence have been given in table 56. A further analysis of the material (table 89) 
presents the numerical relations of the principal color-classes in each and every 
valley. All of these colonies will be discussed in the summary at the end of this 
section; in describing them in detail, only the larger collections will be analyzed, 
and little attention will be given to valleys like Faaripoo, Mahaena, and Tehoro, 
where one or only a few shells of this variety were taken. 
TaBLeE 89.—Partula otaheitana rubescens. Numerical relation of the principal color-types. 
Reddish Total No. Yellow Reddish 
of adults. class. class. 
Total No. Yellow 
of adults. class. 
RY PTT |e Oe nee | ee a Obmm ee tuutar. varia. cy.tereres 5 
eT | ee 4 On | Cn | | 7 a | | SLOT Secured doioacieanel Kelle 2 1 
Haat poosedereiilerciee- 2 1 ARINC ooncoooec. 1 aa a 
PAYNANGOs Gc0d0000006 342 105 SRE, - -oooneeeue 214 2907 7 
Farapa. weet e tees ches ADA, oo on onnaon. 82 376 6 
Faarumai Be iO acne 19 fan ING TREAcososcncoooe 1 a 
Tiarei..........-.., 15 11 ura ee nee 119 4101 18 
RW Aos coo sasenne 89 67 Oopun ee rena 272 5126 5146 
haatautiaseeeeeeeene 0 in Apirimaue........... 1 a: 1 
Rapeiharrrreiericiicr 
lWhitish 10, yellowish 61. *Vellow, clear apex, 81; yellow, red apex, 20. 
2Vellow, clear apex 54; yellow, red apex 153. 5See detailed description. 
®Vellow, 23; orange, 53. 
That there should be such striking variations in the absolute frequency of this 
form is a fact which should not be passed over as insignificant; it is the same fact, 
with an identical meaning, that was discussed at some length in the section dealing 
with Partula hyalina. No claim is made that the figures given for the several 
valleys are absolutely exact indications of the real frequencies of rubescens, for larger 
series would undoubtedly show differences. Yet, so far as they go, they have an 
approximate if not a final value for the problem dealing with environmental influ- 
ence. Ina word, the marked change in the prevalence of rubescens, in passing from 
Papenoo to Farapa and Faarumai, or from Papeiha to Utuufai, must be interpreted 
as indicating a real constitutional difference in colonial vigor, on a plane with con- 
genital variations in respect to size and shape and color. Beyond the limits set by 
environmental conditions to the existence of any snail-life whatsoever, external 
circumstances do not seem to cause variations in numerical abundance. 
TUAURU AND AHONU VALLEYS. 
The shells of Tuauru are only few in number, but they are interesting as being 
the first-found rubescens beyond the range of amabilis. In correspondence with 
this juxtaposition, they display qualities that are transitional from amabilis to the 
larger and more characteristic rubescens of Ahonu Valley, which occur in greater 
relative abundance. Three examples of the Tuauru series are given in plate 26, 
figs. 51 to 53. The colors are duller than in the valley beyond, and the absolute 
