Darwin-Hooker Letters : Letter from C. R. Darwin to J. D. Hooker 12 [April 1859]
Darwin, Charles Robert
Darwin-Hooker Letters
<p style='text-align: justify;'>CD agrees cultivated plants may begin to vary after some time and then may vary suddenly, but cautions JDH on lack of evidence. His explanation is that small variations are ignored until they accumulate.</p>