52 PUOCEEDINGS OF THE 



ill ii large glass bottle placed by a window witb a sunny outlook 

 behave as described. But tlie conditions are not normal. Iris 

 Pseudiu-orus is sucb a bardy plant, so well-known in England as 

 a late spring and early summer ornament, that no description 

 and no botanical details are necessary. That sucb marked 

 cban<;es should have taken place in the germination of the seeds 

 of the Yellow Water-Flag without having attracted the attention 

 of gardeners, seedsmen, and botanists seemed to me very 

 strange— indeed, almost incredil)le. It is to Mr. Dymes that I 

 owe the seeds which by their growth show, I think quite clearly, 

 that Iris Pseudacorus has not been attempting any " mutations " 

 and may still be trusted to produce seedlings in mud and shallow 

 water — seedlings which are normal and healthy. If placed in the 

 environment selected by Mr. Dymes, the floating seeds germinate ; 

 but if you will compare the seeds grown inside the house, grown 

 in comparatively deep water, with those grown out-of-doors 

 under normal conditions, I think you will agree with me that the 

 former are neither healthy nor normal. The root-system is 

 different and poorly developed, the leaves are pale and lacking in 

 chlorophyll, and the plant is generally deformed. Of the seeds 

 kindly given to me by Mr. Dymes (Dec. 1916) I placed eight 

 (without any choice as to shape) in artificial pond No. I. This 

 contained mud and weeds, was always kept saturated with water 

 when that was necessary, and freed from superficial water when 

 the bowl became filled by rain or snow. Pond No. I represented 

 the mud at the margin of pond, marsh, or stream. Seven seeds 

 were placed in Pond No. II. This contained the same amount 

 of mud, but when the seeds w^ere introduced they floated on the 

 superficial water 2 inches deep. During the winter, with its 

 rain, snow, and frost, these seeds sank and rested hghtly on the 

 mud. A little later six seeds were floated on water about 

 10 inches deep ; the bottle in wdiich they Avere placed has been 

 standing on a table in my dining-room in front of a window 

 facing south and south-west. Ponds I and II are in my garden. 



The first signs of germination appeared on May the 19th, 1917, 

 in the seeds floating in the bottle — a state of things due, no 

 doubt, to higher temperature in the dining-room, and assisted by 

 a position exposed to our intermittent sunlight. Three seeds 

 germinated on that day, and the other three during the following 

 week. These seedlings throw out a long root, as described by 

 Mr. Dymes. The mass of fibrous roots given off by normal 

 seedlings is quite absent. As these floating seedlings increase 

 in size and weight, they sink. Two, caught in water-weeds, have 

 given up the struggle and are dead. Two lie on the bottom, on 

 a thin layer of mud : they will, I expect, die during the winter. 

 Two are still to be accounted for : I show you these two as dried 

 specimens. 



On May the 26th seeds in Pond No. II, those lying on mud in 

 shallow water, b?gan to sprout. In course of time seven fine 

 seedlings appeared in that ])ond. Lastly, the seeds in the mud of 



