DIURNAL MOVEMENT OF MIMOSA 



595 



The responses of Mimosa on the cessation of light 

 described above took place in the course of experiments 

 which lasted for more than six hours. Objection may be 

 raised that during this long period the temperature varia- 

 tion must have produced certain effects on the response^ 

 In order to meet this difficulty, I carried out the following 

 experiments which were completed in a relatively short 

 time. I have already explained how the period of ex- 

 periment could be shortened by suitable increase of the 

 intensity of light. The experiment was commenced inside 

 a room at noon and completed by 2 p.m.; the temperature 

 variation during this periovl was less than 1°C. 



After-effect at pra-maximum : Eri^erimetit 227. — Light from 



Fig. 218 Fig. L'l'.i Fig. -."JO. 



Fig. 218. — Pre-maximum after-effect of light in Mimosa. 



Fig. 219. — After-effect at maximum. 



Fig. 220. — Post-maximum after-effect exhibiting an 'over-shooting' below 

 position of equilibrium. 



In the above records light was applied at arrow, and stopped at the second 

 arrow enclosed in a circle. 



an 100 c.p. incandescent lamp was focussed on the upper 

 half of the pulvinus of Mimosa for 8 minutes, after whic 



