I do not say 'fittest,' because it is ordinarily understood to mean that the survivors have some _morphological features_, by which they are benefited, which lead on finally to specific characters. I do not find this to be the case. Take an instance of great contrast. Sow 100 seeds of the water (submerged) _Ranunculus fluitans_ in a garden. They _all_ grow up as _aërial_ plants, _i.e._ they vary as they grow precisely in the same way. It is only the _weakest_ (from badly nourished seeds) which get crowded out of existence. Here, then, is _definite variation without the aid of natural selection_. _Ex uno disce omnes._ 2. _Delimitation of varieties and species_ by the _non-reproduction_ of intermediate forms. It is generally said that if 'good species' are isolated, the intermediate forms have been killed off by natural selection. I maintain that they were _never reproduced_. Thus if A has passed by successive generations, A′, A″, A‴, &c., to A^n; A and A^n being now only in existence, then A′, A″, &c., represented a _single generation_ apiece, each offspring being one degree nearer to A^n, but could never be reproduced, as the environment was continually acting upon the whole series, urging each generation forwards till it became stable in A^n. This is precisely what takes place in cultivating a wild plant like the parsnip. Each year the grower selects a slightly improved form, till the required type is fixed. The 'Student' is now A^n, a more or less permanently fixed form, each of the intermediate forms, lasting one year, having ceased to be reproduced. 3. The geographical distribution of varieties and species by _self-adaptation_. That is, if a number of plants migrate to a new locality with new environmental conditions, half of them may die; because they cannot adapt themselves; the other half may live--change, and become fixed forms, by their power of adaptation. The final conclusion of the whole is that plants require nothing more than climatic influences, to which their protoplasm may respond. The result is new varietal or specific characters. Then, if the same environment lasts, these become gradually more and more fixed and hereditary, but one can never tell beforehand but that the oldest plant in creation may not change again as soon as it finds a new environment.... This is what a long study of plants and experiments has led me to; and it is not a conclusion arrived at solely by 'thinking out' or evolving from my own consciousness--like the German camel! Hoping you are progressing, Believe me, yours sincerely, GEORGE HENSLOW. Hôtel l'Ermitage, Costebelle, Hyères, France: October 29, 1893.