Apr., 1894.] BOTANICAL SOCIETY OF EDINBURGH. 187 



Miesse (Experiences siir I'lnfluence de la Lumiere sur les 

 Plantes. — Journal de Physique de Piozier, T. 6, Dec. 1775) 

 considered that light has little or no influence on germina- 

 tion. 



Senebier (Memoires Physico-Chimiques, 1782) concluded 

 that light was hurtful to the germination of seeds. 



Ingenhousz held the same opinion as Senebier as 

 to the action of light (Experiences sur la Vegetation, 

 1787-89). 



The Abbe Bertholon (Journal de Physique de Eozier, 

 Dec. 1789) criticises previous experiments on the subject, 

 laying special stress on the necessity of equality in the 

 degree of humidity of the seeds experimented upon. 



Senebier (Physiologic Vegetale, 1800) in subsequent 

 experiments, called forth by the remarks of the Abbe 

 Bertholon, and taking care to adopt the precautions sug- 

 gested by the latter, is led to the same conclusion as 

 formerly. 



E. Lefebure performed many experiments on the action 

 of light, especially with regard to the action of coloured 

 rays. In the latter inquiry he does not arrive at any 

 definite result. He discovers a retardation of germination 

 under the influence of white light. The experiments were 

 made without regard to small differences of temperature, 

 though considerable trouble was taken to secure similarity 

 in the conditions of moisture (Experiences sur la Germina- 

 tion des Plantes, 1800). 



Th. de Saussure (Eecherches Chimiques sur la Vegetation, 

 1804) regarded the action of direct sunlight as hurtful to 

 the seeds on account of the heat which accompanies it, but 

 in diffused light, when every precaution was taken to 

 ensure similarity in the conditions of temperature and 

 moisture, he does not perceive any difference in the progress 

 of germination. 



A. P. de Candolle (Phys. Veget, 1832) thinks that light 

 has no action on the germinative activity. 



Ch. Morren (An. Sc. 'Nat, 1832) considers that obscurity 

 favours the first period of germination. 



Mayen (Neues System der Pflanzen-physiologie, 1837) 

 made experiments with seeds of six different genera of 

 plants, observing equal conditions of heat and moisture 



