570 Hitt: NoTes ON MIGRATORY PLANTS 
they get the start by their superior ability to spread, but with 
which they must subsequently contend ; or because the plants, 
when the ground is well stocked with seeds, come up thickly and 
crowd one another. It is probable, too, that it loses in vigor 
under less favorable conditions. It stands no chance whatever in 
maintaining itself against a growth of the common grasses. 
Lacruca Scariota L. I noticed this first in 1885. It was 
infrequent then, but has since become one of the most common 
weeds, more generally diffused than Sa/sola Tragus, Its copious 
pappus permits its easy propagation, and like the dandelion it 
springs up in pastures and meadows as well as in waste ground. 
But as stock devour it when tender, little comes to maturity in 
pastures, but more in meadows and the neglected parts of culti- 
vated fields. Its stiff and rather prickly habit make it more re- 
pulsive when grown, but even then the leaves are eaten. 
Cutcaco, ILL., April 1902. 
