PARTULA OTAHEITANA. 133 
longer period of the year, while the dextral snails exercise their reproductive ability 
from the end of the wet season onward, like the Fautaua colony. ‘The 1906 speci- 
mens were secured in February and March, and the sinistral members were gravid 
in 79 per cent of the cases, while the contrasted groups showed only 54 per cent of 
its members in the same condition; in 1907, when the collections were obtained in 
July, the gravid dextrals far outnumbered the gravid reversed individuals—76 per 
cent as compared with 69 per cent; finally, in 1909, the former have again fallen 
below the latter in relative productivity. Hence the second interpretation sug- 
gested seems to have more in its favor than the supposition that different hereditary 
rates in fecundity distinguish the snails of the two kinds of coil. 
TaBLeE 66.—Partula otaheitana amabilis, Hamuta Valley. Fecundity. 
Seri Records No. of | Per cent | No. of | No. of | Total Average Average 
CHISS: “| gravid. | of gravid.| eggs. | young. |contents.| for gravid.} for all. 
Sinistra lel 0G saris «oct skerexerocisloherevens acess 38 30 78.95 14 40 54 1.80 1.42 
OO Tiras aciererechoausierecien oie 229 159 69.43 243 165 408 2.56 1.78 
NOOO eer cncsexsnaravsucrevenayeveusyeysner 5 4 80.00 6 6 12 3.00 2.40 
WMextralmel90 Glyae ics sreevoeisels eclilevorode 13 7 53.84 3 8 11 it 57 0.84 
NO Tpemer secs rersreeiebeceisiere eneinoine 149 113 75.84 171 114 285 2) 5 1.91 
OOD Re cree cielo einae e eietelsiaes 9 5 95,59 8 1 9 1.80 1.00 
Sinistralmalliyearserereinmeeraireeiieieiris 272 193 70.95 263 211 474 2.45 1.74 
Mextralwalliyvearstoercrie« siersiyelels te 171 125 73.09 182 123 305 2.44 1.78 
Sinistral and dextral, 1906........... $1 37 72.55 17 48 65 175 1.27 
LOO Tis snows ane 378 272 71.95 414 279 693 2.55 1.83 
L909 isis accuse 14 9 64.28 14 7 21 2.33 1.50 
Sinistral and dextral, all years........ 443 318 71.78 445 334 779 2.45 los 
TasLe 67.—Partula otaheitana amabilis, Hamuta Valley. Numerical relations of the form and 
color classes. 
No. of plain. Percentage of plain. 
Caries No No. of Per cent 
Class | Class | Class | Class banded: Class Class Class Class banded. 
18 II. Ill. IV. Ie Il. III. IV. 
Sinistral, 1906...... 39 4 5 28 2 if 10.2 12.8 71.8 Spel me 
NOO Tie: ess 240 27 43 134 31 5 11.2 17.9 55.8 12.9 734 
NOOO os 20 2 4 10 3 1 10.0 20.0 50.0 15.0 5.0 
Dextral, 1906....... 15 1 ay 14 “ie 6.6 sate 93.3 - 
W907 ees 6 151 34 25 73 17 2 PRD 89) 16.5 48.3 aie?) 68} 
1909....... 9 ays 2 5 2 nine 2D 74 55.5 22.2 
Sinistralsalleeneeee 299 33 52 172 36 6 11.0 17.3 57.5 12.0 2.0 
Dextral, all......... 175 35 27 92 19 2 20.0 15.4 BY4.5) 10.8 1b, i 
Mota Meter crstecos ses 474 68 79 264 55 8 14.3 16.6 55.7 11.6 iad 
It has already been pointed out that Garrett describes the valley colony as 
composed of sinistral snails only, as far as this species is concerned. Either Garrett’s 
mind was focussed on the Pirai Valley situation, or else a great change has been 
effected through the mutative production of dextral individuals by reversed parents. 
Garrett is so meticulous in his descriptions that I am somewhat inclined to adopt 
the latter view. 
