APPENDIX 545 



several species of Juncus, Lycopus europaeus, 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 seed^essels, 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 



