The copy of Edible Wild Plants of Scotland (F. Buchanan White, 1871) on Archive.org begins at page 22 so I don't know what is missing but these words from the introduction are a high-trumpeted claret call to graze the bonny hills. It reminds me of this earlier fragment from Gilbert White.
[I]n civilized nations, it is the naturalist — not the mere classifier of species, nor he who gathers together a collection of objects of natural history as he would a collection of postage stamps, coins, or old china, but the true lover of nature — who is the chief inheritor of this love of the wild freshness of the earth's morning, still lingering on the mountain's side, in depths of the primeval forest, or amidst the waves of ocean. And thus it seems to me that to the naturalist, wild flowers and fruits will always be more beautiful and attractive than all the richest treasures of the garden.Of a completely different time and tone is Emergency food plants and poisonous plants of the islands of the Pacific by Elmer Drew Merrill, issued in 1943, technical manual published by the US War Department. The images are from that book.
But a comparison should scarcely be made, perhaps, between wild fruits and those which have become subject to man. The whole character of the latter has become changed; the bitter has been made sweet, and the small large - all freedom has been lost.