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ItOYAL HORTICULTURAL SOCIETY. 



possible in all cases. There are very variable plants with regular 

 pollen, as Salix nigricans, S. Lapponum, and the bistigmatic 

 Carice3. On the contrary, we have plants with irregular pollen, 

 like hybrids, which are distinguished by the greater or less 

 stability of their productions, as Salix fragilis, Trifolium mon- 

 tanimi, Barbarca vulgaris, but not B. stricta, Potentilla incana, 

 Hierochloe, and many others. But in the greater number of cases, as, 

 for example, amongst hybrids, in many cultivated plants, in many 

 indigenous plants conspicuous for white or light-coloured blos- 

 soms, and finally in a great part of the very variable wild plants, 

 as hawkweeds, roses, the shrubby brambles (but not Bubus ccesius 

 and idceus, which yield no varieties and have regular pollen), mul- 

 tiformity in the pollen and great variability are combined. It is 

 also possible that in the multiformity of the pollen of these plants, 

 we see the variability of their offspring pointed out as it were in 

 embryo, or in other words, the increasing variability of the 

 progeny of hybrid pollen must be referred to an irregular di- 

 vision of the mother pollen-cell as its proximate cause. Mr. 

 Darwin believes that there is some connexion between sterility 

 and variability ; and there is suggestive matter in these observa- 

 tions in other directions. 



Finally, a parallel may be drawn between hybrids and many 

 cultivated plants. A common point in both consists in the fact 

 that they are not fully accommodated to the conditions under 

 which they live. Hybrids are not so because, in consequence of 

 their abnormal generation, they have inherited only a portion of 

 the peculiarities which belong to their accommodation, and culti- 

 vated plants because, from artificial treatment, they are kept in 

 climatic and local conditions for which they were not destined*. 

 The history of all our cultivated plants, so far as it is known, 

 shows this. Transported from free nature into the garden, from 

 a warm into a cold climate, the plant at first preserved its pecu- 

 liarities for a time ; then slight changes crept in ; more followed, 

 till at last, by repeated generation, scarcely one of the individuals 

 from seed is like the other. In this state the pollen of many 



* It should be observed that in a state of nature plants are very frequently 

 found under conditions which are not the most suited to their nature, but in 

 places where they are able to maintain the struggle of life against others by 

 which they would be overwhelmed. This is a fact which is too little attended 

 to by cultivators. Some excellent observations on this subject by the Dean of 

 Manchester will be found in the first volume of the former series of this Journal, 

 p. 44.— Ed. 



