TRANSACTIONS OF SECTION K. 853 



the mud sheltered hy nettles. By September great increase of land plants, solid 

 jungle-like growths 3 to 5 feet high. 



1903. — Heavy rains tbis year assisted the water plants: Scrophilaria locuWy 

 dominant, Myosotis very scarce ; semi-aquatic tend to dominate in the open, 

 Urfica largely where sheltered by willow ; many grasses and Epilobium. Yery 

 mixed communities, e.g. Urtica and Phragmites struggling for dominance ; 

 Phvagmites and Carex covered and nearly swamped by tangles of Galium Aparine ; 

 short Helosciadium and meadow grass forming a thick turf; hummocks of Carex 

 paludosa covered by Humulus Lupulus and Solarium dulcamara. 



The complete list shows eleven frequent semi-aquatics, of which four are 

 locally dominant, as against thirty-two frequent land plants, of which eight are 

 . locally dominant. 



10. The Botany of Upper Peru. By A. W. Hill, M.A. 



FRIDAY, SEPTEMBEB. 11. 

 The following Papers were read : — 



1. New Discoveries in Heredity. By W. Bateson, F.R.S. 



2. Results of some Gross -breeding Exjjerinients with Plants. 

 By Miss Edith Saunders. 



3. Recent Experiments in the Hybridisation of Orchids. 

 By Charles C. Hurst. 



Recent Progress in Orchid Hybridisation, 



First hybrid raised in 1856. One thousand three hundred distinct crosses in 

 1903. Two hundred and thirty generic hybrids. Majority of hybrids fertile. 

 Hybrids of the fourth generation. Hybrids with pedigree of five distinct species. 

 Orchid hybrids offer wide field to the student of inheritance. 



Intermediate Hybrids. 



Writer's experiments with PapMopedilum {Cypripedium). First generation, 

 S X I = SI ; second generation, SI x B = BI + BS. Eesults apparently consistent 

 with Mendel's Principles. 



Dominant Hybrids. 



Mainly confined to generic matings, e.g. Sophronitis x Epidendrum - Epi- 

 dendrum. Infertile and cannot be tested in the light of Mendel. 



False Hybrids. 



Mainly confined to generic matings and all maternal, e.g. Zygopetalum J x 

 Odontoglossum $ = Zygopetalum ; second generation gives same result. Therefore 

 'false hybrids' and not Mendelian 'dominants.' Writer's previous suggestion 

 of parthenogenesis. Comparison with the paternal 'false hybrids ' of Millardet 

 and De Vries. Further experiments into the nature of one-sided inheritance 

 urgently needed. 



