if we admit the view, which seems highly probable, that the conjugation of the Algae and of some of the simplest animals is the first step towards sexual reproduction; and if we further bear in mind that a greater and greater degree of differentiation between the cells which conjugate can be traced, thus leading apparently to the development of the two sexual forms. (10/59.  See the interesting discussion on this whole subject by O. Butschli in his ’Studien uber die ersten Entwickelungsvorgange der Eizelle; etc. 1876 pages 207-219.  Also Engelmann “Ueber Entwickelung von Infusorien” ‘Morphol.  Jahrbuch’ B. 1 page 573.  Also Dr. A. Dodel “Die Kraushaar-Algae” ‘Pringsheims Jahrbuch f.  Wiss.  Bot.’  B. 10.) We have also seen that as plants became more highly developed and affixed to the ground, they would be compelled to be anemophilous in order to intercross.  Therefore all plants which have not since been greatly modified, would tend still to be both diclinous and anemophilous; and we can thus understand the connection between these two states, although they appear at first sight quite disconnected.  If this view is correct, plants must have been rendered hermaphrodites at a later though still very early period, and entomophilous at a yet later period, namely, after the development of winged insects.  So that the relationship between hermaphroditism and fertilisation by means of insects is likewise to a certain extent intelligible.

Why the descendants of plants which were originally dioecious, and which therefore profited by always intercrossing with another individual, should have been converted into hermaphrodites, may perhaps be explained by the risk which they ran, especially as long as they were anemophilous, of not being always fertilised, and consequently of not leaving offspring.  This latter evil, the greatest of all to any organism, would have been much lessened by their becoming hermaphrodites, though with the contingent disadvantage of frequent self-fertilisation.  By what graduated steps an hermaphrodite condition was acquired we do not know.  But we can see that if a lowly organised form, in which the two sexes were represented by somewhat different individuals, were to increase by budding either before or after conjugation, the two incipient sexes would be capable of appearing by buds on the same stock, as occasionally occurs with various characters at the present day.  The organism would then be in a monoecious condition, and this is probably the first step towards hermaphroditism; for if very simple male and female flowers on the same stock, each consisting of a single stamen or pistil, were brought close together and surrounded by a common envelope, in nearly the same manner as with the florets of the Compositae, we should have an hermaphrodite flower.