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XXXIII. 



ON THE GEEMINATION OF THE SEEDS OP SOME 

 DICOTYLEDONS. 



By J. ADAMS, M.A. (Cantab.). 

 (Plate XXXIV.) 



[Read December 17, 1912; Published February 21, 1913.] 



When seeds ripen they are usually carried some distance from tlie parent 

 plant by the agency of water, wind, or animals. If they fall in a suitable 

 habitat, some of them will, after a longer or shorter interval, germinate. 

 One of the objects of the present investigation was to discover liow long the 

 seeds of a particular species lie dormant in the ground before germination. 

 The ideal method of procedure would be to collect the seeds when ripe and 

 to bury them at once in the soil, selecting a habitat as similar as possible to 

 that in which the parent plant was growing. Needless to say, this ideal 

 was not in many cases realized. While most "Floras" of the British Isles 

 give full particulars of the time of flowering of the different species, I am not 

 acquainted with any that give the dates of ripening of the seed. In the 

 case of common plants little inconvenience need result from this dearth of 

 knowledge. The particular species of plant can be easily examined from 

 time to time and observations made on the rate of the ripening of the seeds. 

 But in the ease of a rare species much time may be spent in collecting ripe 

 seeds for purposes of experiment. For example, three different journeys 

 had to be made to a point eight miles from Dublin, in order to obtain seeds 

 of liiibia peregrina. 



Another difficulty is, that some species very rarely produce seeds. In 

 1910 I succeeded for the first time in getting a few seeds of the Common 

 Bindweed {Convolvulus sepium). In 1911 I secured an abundance of seeds 

 of this species; but whether this abundance was the result of the unusually 

 warm summer, I am unable to say. Knuth, in his " Handbook of Flower 

 Pollination," 1906-9, states that the large Bindweed seldom fruits in localities 

 where tlie Hawk Moth {Sphinx Convohuli, Linn.) is absent. Only once have 

 I succeeded in getting what looked like sound seeds of such a common plant 

 as Meadow Sweet {Spircea ulmaria, Linn.), but these were not tested in order 

 to discover whether they were really viable. I have not so far been able to 



SCIENT. PROC. R.D.S., VOL. XHI., NO. XXXHI. 4 A 



