APPENDIX 545 



.several species of Juncus, Lycopus europseus, Mentha aquatica, Ranun- 

 culus repens, Rhinanthus crista galli, several species of Rumex, Scutellaria 

 galericulata, Sparganium ramosum, &c. 



In nearly all the plants that failed to germinate in sea-water the capacity 

 of readily germinating in fresh water was displayed. The restraining 

 power of immersion in sea-water was illustrated over and over again in my 

 experiments. During the course of an experiment seeds removed from the 

 sea-water vessel and placed directly in a vessel of fresh water kept beside 

 the other germinated in a few days, whilst those left in the sea-water never 

 germinated, though often kept there for months after. It was also notice- 

 able that a previous sea-water immersion favoured early germination in 

 fresh water. It may be added that most of the experiments were on 

 floating seeds and seedvessels, though germination also occurred in the 

 sunken state. 



It was ascertained in the exceptional case of Ranunculus sceleratus, 

 that although germination took place in sea-water, it was only after a pro- 

 longed soaking of months had prepared the way. Of a number of its 

 seed-like fruits placed in fresh water and in sea-water in April and kept 

 under the same conditions, those in fresh water germinated freely in a 

 week or two, whilst those in sea-water did not begin to germinate until 

 the following October. Whilst the floating seedlings produced by ger- 

 mination in fresh water grew vigorously and developed roots, those resulting 

 from germination in sea-water and left in the vessel only attained a length 

 of four millimetres in two months, developed no roots, and showed only 

 the first leaf. The sea-water seedlings were pale green, and in their stout 

 fleshy appearance contrasted greatly with the slender fresh-water seedlings. 

 With regard to the germination in sea-water of the plants of the salt 

 marsh and of the mud-flats of estuaries, the following observations may be 

 made. With Aster tripolium the seeds germinate readily in sea-water even 

 when its density is raised by evaporation to i '040 ; and I think that by a 

 carefully graduated series of experiments they could be induced to germinate 

 in brine. The seeds of Salicornia herbacea germinate in sea-water more 

 readily than in fresh water ; and the sea-water seedling is much the more 

 vigorous and healthy of the two. I kept the floating seedlings in sea-water 

 for about ten weeks from the date of germination, when they had developed 

 the second joint and were throwing out rootlets. After that, unless placed 

 in salt-mud, they became sickly and died. The floating seedling can 

 evidently disperse the species. I found with Spergularia marina, the 

 maritime form of S. rubra, that seeds of the plants growing on a sandy 

 beach did not germinate in sea-water, only those from plants growing on 

 muddy coast-flats doing so. But the sea-water seedlings, unlike those of 

 Salicornia herbacea, but like those of Ranunculus sceleratus, when left in 

 sea-water did not thrive. The seeds of Triglochin maritimum, as well as 

 those of T. palustre, behave very similarly in sea-water, germinating 

 readily, the liberated seedlings thriving afloat and producing the plumule. 

 VOL. II N N 



