14 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



attached to the coltsfoot must have extraordinary powers 

 of fixing 1 nitrogen. 



I next note a grass, Agrostis alba, the scutch, or couch, 

 or twitch, with its decumbent rooting stems, common 

 alike to salt swamps below high water mark, and to waste 

 land, and even fresh water. This, too, thriving at Widnes 

 luxuriantly seems to have powers I should like to look 

 into. So has the grass Triticum re-pens, whose dwelling 

 is even on the edge of acid water beknv a " waste 

 tip." The same I have mentioned about the common 

 dog-daisy, Matricaria inodora, and the Orache, and also 

 the silvery leaved Potentilla anserina, equally at home on 

 the highway and on the shore. 



I may be making too much of saline conditions, but 

 it seems that under certain circumstances common salt 

 does decompose into nitrate of soda. Anyhow, I should 

 be interested to know how the maritime plants manage it, 

 and to see if the principle can be applied to more useful 

 plants. Poverty of soil may prove a mere matter of 

 poverty of brains. 



Two plants slightly more dependent on soil contrive to 

 exist in towns. If ever the grass grew in the streets of 

 Liverpool, Poa annua would be the first species, and also 

 the large plantain, Plantago major, and the knotgrass, 

 Polygonum a vie id are, all of which have so inured them- 

 selves to trampling that they hardly seem to exist where 

 they or the ground they live in are not well kicked at 

 some period or other. But, like many other humble 

 things, they have a marvellous knack of picking up a 

 living. 



Another plant I should like to mention, though it is 

 not a weed, but one of the most aboriginal heathen, is the 

 common London pride, Sa.vifraga umbrosa, if, without 

 injustice to Ireland, I may call St. Patrick's cabbage by 



