CONDITIONS OF FLOWERING 99 



from their fellows as being distinguished for the purity of 

 their colouring. 



Another problem, of no less interest, is to determine the 

 conditions most likely to ensure the germination of seeds. 

 Generally speaking, the seed of a species, when fertilised 

 with its own pollen, germinates readily, but hybrid seeds 

 are apt to lie dormant for years. The longest time for 

 which an Iris seed has been known to lie dormant in the 

 ground before seeing fit to germinate is eighteen years. 

 This happened with one of Sir Michael Foster's hybrids 

 only a few months before his death, and instances of seeds 

 germinating after several years are by no means unknown 

 to any who have engaged in the fascinating pursuit of rais- 

 ing Irises from seed. 



It would be useful, too, to know the conditions which 

 would induce more Irises to flower again in the autumn. 

 Is this character an idiosyncrasy of the individual plant, or 

 is the second flowering brought about by any external 

 circumstances ? The author once raised an /. pumila from 

 seed, which germinated early in spring, and flowered in the 

 month of October in the same year. It is well known that 

 these autumnal displays can be obtained, given a favourable 

 autumn, by timely sowings in the case of other perennials. 

 Delphiniums, for instance, sown in the open in spring, and 

 transplanted early, often make a brave show of spikes in 

 October. Irises, however, cannot be relied upon to flower 

 as soon as this, but is it possible by refusing, for instance, 

 to allow a plant to flower in the spring, or by special treat- 

 ment during the summer, to ensure an autumn display of 

 flowers ? It is a question worth some thought. 



A query for those who seek to find adaptation in every- 



