Thiselton-Dyer.— Morphological Notes . 153 
I may add that I subsequently heard of cases occurring 
elsewhere than at Sandringham in 1898. It is possible, 
therefore, that there were some conditions in the season of 
that year that were favourable to their happening. 
Precocious germination occasionally happens in the orange 
and other species of Citrus , and appears to be not infrequent 
in the papaw ( Carica Papaya) ; an instance is figured in the 
‘ Gardeners’ Chronicle ’ for December 10, 1887, p. 717. But in 
the vast majority of cases seeds remain in a dormant con- 
dition for a considerable time after maturity. This is no 
doubt an adaptive character which has been acquired in order 
to facilitate their dispersion to considerable distances. It 
might be expected, therefore, that in the case of gregarious 
plants whose seeds grow where they fall precocious germina- 
tion might occur. It is actually met with amongst the 
Dipterocarpeae ; Blume figures a case in Dipterocarpus re- 
tusus 1 . It is especially characteristic of the mangroves 
( Rhizophoreae ). In the case of Rhizophora itself I quote the 
following from Brandis’s ‘Forest Flora/ p. 217 : — 
‘ Germination takes place in the fruit on the tree, the 
radicle protrudes soon after flowering as a long cylindrical 
body, thicker near the end, attains a length of 12 in. or more, 
and at length roots in the mud when the fruit falls.’ 
In Bertholletia excelsa , which has been described by Mr. 
Watson 2 , the woody pericarp makes it imppssible for the 
seeds to be dispersed before germination. This, therefore, 
takes place in situ , and the surviving seedlings are liberated 
by the final disruption of the decayed pericarp. 
Something of the same kind would probably happen in 
the case of the melon. Its feral form would have a pericarp 
less succulent than that developed in cultivation ; this would 
be penetrated by the roots, which would thence reach the 
soil, and the pressure exerted on the pericarp by the growing 
seedlings would eventually set them free by its disruption. 
1 Flora Javae : Dipterocarpeae, tab. ii ; reproduced in Engler and Prantl, 
Pflanzenfamilien, vol. iii. 6, p. 256. 
8 Annals of Botany, vol. xv. pp. 99-162. 
