ADDITIONAL EVIDENCE 



141 



DIAGRAM ILLUSTRATING THE DIFFERENT BEHAVIOURS UNDER A GREAT 

 VARIETY OF CONDITIONS OF INTACT AND PUNCTURED SEEDS OF 

 CANAVALIA OBTUSIFOLIA OF THE IMPERMEABLE TYPE. 



(The experiment extended continuously from August 14 to October i, and was 

 carried out in England.) 



In one case the seed-coats were punctured in several places. 



In the other case the coats were left intact. 



Nine or ten seeds were employed in each experiment. 



The first fall in weight was due to the seeds having been previously kept under less 

 dry conditions, the small loss in the case of the seeds with coats intact being probably 

 connected with tissue adherent to the scar. The loss in weight of the punctured seeds on 

 September 18 after being exposed for three hours to moist air in the oven at a temperature 

 of 150 F. is remarkable. The punctured seeds here displayed a caving-in or collapse of 

 their coverings around each puncture. A vessel of water was placed in the oven during 

 the test, and after cooling down the inside of the oven was covered with moisture. 



ultra-dry ness. None of the seeds germinated at the close of 

 the experiment, a negative fact which probably depends as 



