M. Ch. Naudin on Hyhridity in Plants, 223 



Dianifest in Nicotiana glauco-angustifoUa (and it would un- 

 doubtedly have been the case with N. glauco-macrophylla if 

 the experiment had been made on it), where the whole 

 pollen mass is defective and inert, whilst the ovary be- 

 comes filled with seeds, when it is fertilised with the pollen 

 of N. Tahacum and N. macrophylla. 



All the hybrids I have observed, containing well-developed 

 grains of pollen in their anthers, have been fertile, often to 

 a high degree, by their ovaries. I have never seen, and I 

 do not believe it possible to mention a single instance in 

 which, the ovary being sterile, the stamens have been fertile, 

 even in the least degree. 



The deleterious influence which hybridisation exercises 

 upon the fertilising apparatus shows itself in different 

 forms. 



The most common, or at least the most remarkable case, 

 is the direct atrophy of the pollen in the anthers, more 

 rarely the atrophy of the anthers themselves ; but we have 

 also seen it act on the entire flowers. It is so among all 

 the hybrids produced by the agency of Datura Stramonium^ 

 the flowers in the lowest branches invariably fall without 

 opening ; also among all tlie individuals of Luffa acutangulo- 

 cylindinca of the first generation, — all the primary male 

 flowers perish entirely, and also some flowers which begin to 

 open when the plants are more than full grown, and have 

 lost part of their vigour. The same phenomenon is observed 

 in Mirahilis longijloro-Jalapa^ which loses three-fourths of 

 its buds, in Nicotiana rustico-paniculata and paniculatO" 

 rustica of three consecutive generations, &c. In fine, an- 

 other mode of sterilisation is that effected by the changing 

 of monoecious male flowers into female, as we have seen in 

 Luffa hybrids of the third generation. 



I have every reason to believe, although I cannot posi- 

 tively affirm so, that the specimen of Cucmnis Figarei, 

 so remarkably large, and peculiar by the nearly total 

 absence of male flowers, which I experimented on in 1856, 

 and which yielded the results I have mentioned, owed both 

 its great size and almost female unisexuality to hybridi- 

 sation. 



