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SELF-FERTILIZATION OF PLANTS. 343 
And he compares Tropeolum minus and Salvia coccinea with Limnanthes Douglasii and 
others, as examples. Such * irregularities ;" as these flowers possess I regard as simply 
necessary consequences of the visits of insects which have brought them about; but the 
amount of * profit" gained by intercrossing would depend upon the degree of benefit 
derived from the infusion of new constitutional elements by the aid of foreign pollen. 
© The larger and more conspicuous a flower, the more frequent are probably the visits 
of insects, while inconspicuous flowers are rarely and, in many cases, never visited by 
them. This led H. Müller to say that they must be self-fertilizing or they would 
‘become extinct; and Mr. Darwin supports his conclusion that small and inconspicuous 
flowers are completely self-fertilized. My own observations fully corroborate the state- 
ment. Mr. Darwin adds, ‘The converse of the rule that plants bearing small and in- 
conspicuous flowers are self-fertile, namely, that plants with large and conspicuous 
flowers are self-sterile, is far from true." This is, of course, equivalent to my former 
statement that very few flowers are self-sterile; and this speaks volumes in favour of the 
enormous advantage, as far as propagation by seed goes, of self-fertilization ; and let us 
not forget that propagation is not only, to use Mr. Darwin's expression, of “ paramount 
importance," but is the sole end of plant life. 
There are several reasons why inconspicuous flowers are not likely to be intercrossed 
by insects. 1, their unattractiveness; 2, the absence of honey-secreting organs; 3, the 
want of scent; 4, they frequently do not expand, or at most remain but half-open, espe- 
cially in cold or inclement weather, while perfectly cleistogamous flowers are, of course, 
never open; 5, their structure sometimes would seem absolutely to prevent the ingress 
of insects (such appears to be the case with Polygonum Convolvulus and P. Hydro- 
piper, the flowers of which seem to be always closed, and with many others). ~ 
Such being the case, whence is the origin of inconspicuous flowers? On inspecting a 
— list of British plants only, it will be seen how nearly, if not absolutely, every large order 
has some genera with inconspicuous species; or else there are some genera with incon- 
spicuous flowers in an order otherwise characterized by conspicuous flowers. The idea that 
they are further differentiated forms at once recommends itself. This is especially the case 
with such plants as Fumaria, Trifolium, Salvia, and many others; for certain species are 
highly self-fertile and quite inconspicuous, but yet have retained the form of the corolla 
so perfectly adapted for insect-agency in their more conspicuous allies. Hence I would 
venture to generalize, and say that all of our existing inconspicuous flowers are more 
differentiated than the latter * and are not primitive forms. I would herein add my 
belief that the Incomplete of Dicotyledons do not represent, nor are they survivals of 
primitive types, but further advanced states of “degradation.” Thus of the “ Cyclo- 
spermez" t, the orders usually included in the Incomplete represent very degraded forms 
of Caryophyllez. In other words, I believe self-fertilization was the primitive condition, 
* I will use the word “ degraded," though it be liable to misconception ; for the popular sense of the term implies 
some kind of “ degeneration." I shall regard it, however, as equivalent to the expression in the text, involving, 
moreover, the idea of reversion, so far as the reacquiring self-fertilization is concerned. ** Degradation” will there- 
. fore solely refer to the more or less Ee condition of the Um &e., and not at all imply degeneracy or 
impaired constitutional phenomena. 
T* Éléments de Botanique; par P. Duchartre, 2™ éd., p. 1135. aw "o 
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