342 
ON CROSSES AND 
sons, which I did not pretend to be able to develope, but 
undoubtedly depending upon certain affinities either of 
structure or constitution, there was a greater disposition to 
fertility in some than in others. Subsequent experiments 
have confirmed this view to such a degree as to make it 
almost certain that the fertility of the hybrid or mixed off- 
spring depends more upon the constitutional than the closer 
botanical affinities of the parents. The most striking and 
unanswerable proof of this fact was afforded by the genus 
Crinum, which is spread round the whole belt of the globe, 
within the tropics and within a certain distance from them, 
under a great variety of circumstances affecting the consti- 
tution of individuals, which nevertheless readily intermix, 
when brought together by human agency. The plant called 
Crinum Capense (formerly Amaryllis longif'olia), impreg- 
nated by either Crinum Zeylanicum or scabrum, both at 
that time also called Amaryllis, produced offspring, which 
during sixteen years proved sterile, probably because, not- 
withstanding their botanical affinity, the first is an extra- 
tropical aquatic plant, and the two latter tropical plants 
which affect drier habitations and readily rot, at least in 
this climate, in a wet situation. The same C. Capense, im- 
pregnated by Crinum pedunculatum, canaliculatum, or 
defixum, produces a fertile cross, though they are so dis- 
similar as to have been placed in different genera, and the 
author was formerly reproached by botanists as having com- 
mitted an absurdity when he insisted upon uniting them. 
The reason of the fertility of their joint produce seems to be, 
that they are all aquatic or swamp plants ; and it may be 
further observed that the crosses with the two former, the 
plants being all extra-tropical, are much more fertile than 
that between C. Capense and defixum, because the latter is 
a tropical plant. The mules between Scabrum and Capense 
having continued so many years with every appearance of ab- 
solute sterility, without any change of situation or treatment, 
at last produced one good seed in 1834 and another in 1835. 
These facts were of such an overbearing nature, that it be- 
came impossible for those, who had charged the author with 
absurdity for uniting the parents under the genus Crinum 
(to which even certain other plants were then asserted to be 
more nearly allied than the species at that time called Ama- 
ryllis), to contend any longer that they, producing a fertile 
