My doubts are now lessened, thanks to a kind communication from M. Ed. André. I may mention first, that I have seen specimens from Mexico gathered by Botteri and Bourgeau, and that authors often speak of finding the species in this region, in the West Indies, in Central America, and New Granada. It is true, they do not say that it is wild. On the contrary, they remark that it is cultivated, or that it has escaped from gardens and become naturalized.[871] Grisebach asserts that it is wild from Peru to Mexico, but he gives no proof. André gathered, in a valley in the south-west of Ecuador, specimens which certainly belong to the species as far as it can be asserted without seeing the fruit. He says nothing as to its wild nature, but the care with which he points out in other cases plants cultivated or perhaps escaped from cultivation, leads me to think that he regards these specimens as wild. Claude Gay says that the species has been cultivated in Chili from time immemorial.[872] However, Molina, who mentions several fruit-trees in the ancient plantations of the country, does not speak of it.[873] In conclusion, I consider it most probable that the species is indigenous in Ecuador, and perhaps in the neighbouring part of Peru. +Oranges and Lemons+—_Citrus_, Linnæus. The different varieties of citrons, lemons, oranges, shaddocks, etc., cultivated in gardens have been the subject of remarkable works by several horticulturists, among which Gallesio and Risso[874] hold the first rank. The difficulty of observing and classifying so many varieties was very great. Fair results have been obtained, but it must be owned that the method was wrong from the beginning, since the plants from which the observations were taken were all cultivated, that is to say, more or less artificial, and perhaps in some cases hybrids. Botanists are now more fortunate. Thanks to the discoveries of travellers in British India, they are able to distinguish the wild and therefore the true and natural species. According to Sir Joseph Hooker,[875] who was himself a collector in India, the work of Brandis[876] is the best on the _Citrus_ of this region, and he follows it in his flora. I shall do likewise in default of a monograph of the genus, remarking also that the multitude of garden varieties which have been described and figured for centuries, ought to be identified as far as possible with the wild species.[877]