664 R. C. PUNNETT. 
No. of Specimens 
Genito-hepatic length 

é nek 4 (Gk Parole : 
Collar length Mean for Group 1 = 4:94 38 
” ” ” 2 = 4:90 33 
” » ” 3 = 484 15 
Average 4:90 
Total length 
Gollanilerent? Mean for Group 1 = 23:1 19 
” ” ” 2 = 22:4 ile 
” ” ” 3 = 23-4 13 
Average 22°9 
An examination of the above table brings out clearly the important fact that two of 
the three ratios, ie. those of the genito-hepatic and total lengths, are quite unaffected by 
growth changes, whilst that of the branchial region is not greatly affected. Neglecting 
group 4 in which there are so few specimens there is a gradual rise in the ratio with 
increase in size from 2°08 in group 1 to 2°18 in group 2, and 236 in group 3. There is 
therefore an increase of about 12°/, in group 3 as compared with group 1, an increase 
sufficiently well-marked though not very great when we take into account the unavoidable 
roughness of the measurements. A possible source of error must be noticed here. A con- 
siderable number of specimens (some 8—10°/,) were regenerating. Where this process was 
obviously at work the specimens were not mcluded in the above measurements. In the 
latest stages, however, regenerated individuals are impossible to distinguish from ordinary 
ones with a somewhat shorter branchial region than usual. As regeneration is far more 
common in the smaller specimens it seems almost certain that the values of the ratio for 
groups 1 and 2 are somewhat too low in comparison with those of group 3. On the whole 
it would appear from these measurements on laccadivensis that the proportions of the body 
of this Enteropneust are very little, if at all, Hable to alteration during the later stages 
of growth. 
This conclusion is borne out by a similar series of measurements made on Pt. flava, 
var. maldivensis. The 52 specimens of this variety were divided into three groups of which 
the last contained only the five largest specimens (see Table 13, p. 674). On taking the 
mean for the three ratios in each group the following figures were obtained. 
TABLE 7. 
No. of Specimens 
Branchial length 
ey Mesnetorran = 165 
Collarslencth Mean for Group 1 = 1 19 
” ” ” 2 = 1:62 28 
Ao nS »  & = 2:00 5 
Average 1°67 
Genito-hepatic length 

Gallarmeneth Mean for Group 1 = 4°58 19 
” ” ” 2= 414 28 
” ” ” 3 = 5:23 5 
Average 4°41 
Total length 
Collar length’ 


Mean for Group 1 = 165 
” ” ” 18°7 
” ” ” 3 = 17°6 2 
Average 17°7 
bo 
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