478 ON TWIN HYBRIDS. 



laeta; the other is more hairy and has furrow-shaped leaves, and is 

 designated as 0. velutina. 



5. 0. laeta and 0. velutina are produced by the combinations 0. 

 biennis x Lamarckiana and 0. muricata x Lamarckiana, and by 

 those of some of their derivatives. 



6. They are produced in about equal numbers. 



7. They remain constant in the second generation. In the only 

 ascertained case they also showed themselves so in the following 

 generations. 



Amsterdam. 



(Botanical Gazette 44:401-407, December igoy.) 



