Origin of Species Variorum

to plants I have recently shown that species in several widely distinct orders present two or even three forms, which are abruptly distinguished from each other in several important points, as in the size and colour of the pollen-grains; and these forms, though all hermaphrodites, differ from each other in their reproductive power, so that for full fertility, or indeed in some cases for any fertility, they must reciprocally impregnate each other. Although the forms of the few dimorphic and trimorphic animals and plants which have been studied are not now connected together by intermediate links, it is probable that this will be found to occur in other cases; for Mr. Wallace observed a certain butterfly which presented in the same island a great range of varieties connected by intermediate links, and the extreme links of the chain closely resembled the two forms of an allied dimorphic species inhabiting another part of the Malay archipelago. Thus also with ants, the several worker-castes are generally quite distinct; but in some cases, as we shall hereafter see, the castes are connected together by graduated varieties. It certainly at first appears a highly remarkable fact that the same female butterfly should have the power of producing at the same time three distinct female forms and a male; that a male Crustacean should generate two male forms and a female form, all widely different from each other; and that an hermaphrodite plant should produce from the same seed-capsule three distinct hermaphrodite forms, bearing three different kinds of females and three or even six different kinds of males. Nevertheless these cases are only exaggerations of the universal fact that every female animal produces males and females, which in some instances differ in so wonderful a manner from each other.