In the summer of 1838, Charles Darwin considered marriage. The disadvantages included losing the 'freedom to go where one liked', while staying single would mean avoiding 'the expense & anxiety of children'. But then, he reflected, 'only picture to yourself a nice soft wife on a sofa with good fire, & books & music perhaps'. Not to mention an 'object to be beloved and played with. better than a dog anyhow'. Wedlock won; within months he was engaged and then married to his cousin, Emma Wedgwood. The pairing brought anxieties, however, especially over whether marriage between such close relatives would issue in unhealthy children. As a philosophical naturalist, Darwin had long been interested in reproduction or 'generation', to use the term of the day. Generational issues would eventually lead him to study subjects as diverse as barnacles, flowers, pigeons and domestic animal and plant breeding. His hypothesis of pangenesis, probably first formulated in 1841 but only published in 1868, was an attempt to give a unified account of all kinds of generation, from the healing of wounds in trees, to propagation by buds and grafting, to sexual pairings and fertilisation. Moreover, in Darwin's view, since sexual pairings - whether decided by male combat or female choice - were selective, they enabled a selectional evolutionary process separate from, and sometimes in tension with, natural selection.