Again in _Petunia_ Miss Saunders's[4] work has shown that a somewhat similar state of things exists, but with this remarkable difference, that though the egg-cells are mixed, singles and doubles, the pollen-grains are all _singles_, viz: dominants. All the _Petunias_ yet examined have been in this condition, including some which in botanic gardens pass for original species. Whether actual wild plants from their native habitats are in the same state, is not yet known, but it is by no means improbable. The case may be compared with that of the moth _Abraxas grossulariata_ studied by Doncaster and Raynor, in which the females are all heterozygous, or we may almost say "hybrids" of _grossulariata_ and the variety _lacticolor_. Similarly we may say that at least garden Petunias are heterozygous in respect of singleness. The proof of this is of course that when fertilised with the pollen of doubles they throw a mixture of doubles and singles. The statements which de Vries has published regarding the behaviour of several of the _Oenotheras_ go far to show that they must have a somewhat similar organisation. On the present evidence it is still quite impossible to construct a coherent scheme which will represent all the phenomena in their interrelations, and among the facts are several which, as will appear, seem mutually incompatible. The first indication that the _Oenotheras_ may have either mixed ovules or mixed pollen appears in the fact that _Lamarckiana_ and several of its "mutants" used as males, with several other forms as females, give a mixed offspring. For example, de Vries (1907) found that _biennis_ [F] × _Lamarckiana_ [M] _biennis cruciata_ [F] × _Lamarckiana_ [M] _muricata_ [F] × _Lamarckiana_ [M] _biennis_ [F] × _rubrinervis_ [M] _biennis cruciata_ [F] × _rubrinervis_ [M] all give a mixture of two distinct types which he names _laeta_ and _velutina_, consisting of about equal numbers of each. On account of the fact that the two forms are produced in association de Vries has called these forms "twin hybrids," a designation which is not fortunate, seeing that it is impossible to imagine that any kind of twinning is concerned in their production. The distinction between these two seems to be considerable, _laeta_ having leaves broader, bright green in colour, and flat, with pollen scanty, while _velutina_ has leaves narrower, grayish green, more hairy, and furrow-shaped, with pollen abundant.