IN THE TROPICS. 
401 
Considering now the various characters summarized in this table,, 
we observe that the average length of the internodes shows a fairly 
continuous variation ; and we may remember that this length was 
not very different in the two parental strains. 
Width of pod is a character which almost certainly exhibits Men- 
delian segregation in spite of a good deal of apparently indefinite 
variation. Unfortunately no actual measurements were made in F a , 
but the plants with distinctly narrower pods were separated by eye 
from the remainder which had wider pods. There were 19 of the 
former and 65 of the latter. Out of 13 of the former, the seeds of 
which were sown, 9 plants produced only offspring with narrow pods 
(13-16 mm.), whilst the remaining 4 plants appeared to have been 
heterozygotes with exceptionally narrow pods. Out of the 31 plants 
with wider pods which were examined none gave rise only to offspring 
with narrow pods. Nine gave rise to offspring all wide podded (17 
mm. and upwards), whilst the remaining 22 plants gave rise to both 
kinds of offspring. It seems clear therefore that Mendel’s law is here 
followed in spite of much variability and in spite of the intermediate 
position of the heterozygote. 
As a general rule wide pods contained flattened seeds and narrow 
pods contained cubical or spherical seeds ; though in this point too 
there was a certain amount of variability. The only exceptions were 
a few cases in which seeds classed as round or cubical appeared in 
pods which were classed as wide. In such cases, when the seeds 
were grown, it appeared that the plants were heterozygotes in respect 
of pod width. 
Seeds with white testas were usually smooth or slightly pitted, 
whereas coloured seeds were always markedly dimpled. 
In the case of some of the above characters the distinction of the 
allelomorphs is certainly open to criticism. In such cases it is not 
absolutely proved that Mendel’s law is followed, although the pro¬ 
bability may be very great that this is so. In other cases the discon¬ 
tinuity is complete, and in these cases the evidence that Mendel’s law 
is followed is complete also. 
Thus, in the case of the presence or absence of a parchment layer in 
the pods, Mendel’s results were fully confirmed, with the exception 
