Immigration of Animals and Plants. 91 
ponaria Vaccaria), the Corn Cockle (Lychnis Githago), the Canada Thistle (Cir- 
sium arvense), bristly fox-tail grass (Setaria verticillata), and the Orab 
Grass (Eleusine indica), a native of India, now spread all over the tropic and 
the warmer temperate zone. 
Since 1880 a number of adventive plants were observed, which may partly 
naturalize, partly again disappear: The Field Pennygrass (Thlaspi arvense), 
the small flowered Cransbill (Geranium pusillum), the Yellow Sweet Clover 
(Melilotus officinalis), the Alfalfa or Lucerne (Medicago sativa), the common 
Carrot (Daucus carota), the Thoroughwax (Bupleurum rotundifolium), the 
Ripple Grass (Plantago lanceolata), the Dead Nettle (Lamium purpureum), the 
Corn Gromwell (Lithospermum arvense), the Thorn Apple (Datura Stramoni- 
um L), the poison Hemlock (Conium maculatum), the Prickly Lettuce (Lac- 
tuca scariola), the two last are observed only this year, 1886. 
The white-flowered Thorn Apple, now common in the east, came no doubt 
from the old continent; but whether the purple-flowered, our troublesome 
Jamestown weed, is indigenous or came from South America, that is, so I 
think, an undecided question; certainly the immigration must be very remote. 
I learned from farmers that the plant springs up in newly-broken land, far 
from any other settlement. The seeds are heavy and not easy disseminated 
very far, but they are known to keep their germinating power a long time, 
and it is very probable that they, a long time ago, were buried in the ground 
before they had a chance to germinate, 
There are some other plants, the immigration of which is doubtful: Ceras- 
tium, triviale of Link, which is the Cerastium viscosum L. in Gray’s Manual 
and in Linnzus’ Herbarium, but C. vulgatum in his Species Plantarum. 
[Linnzeus, by a regretful mistake, interchanged the names of the two plants, 
and I think it is only right to discard ambiguous or inadequate names with- 
out regard of priority. The Cerastium Vulgatum L. herb in Gray’s Manual 
should be changed into Cerastium Glomeratum of Thuillier.] When I first 
found this plant, it was on a place where not likely imported plants grew at that 
time. Nota few plants common to Europe and North America are considered 
to have immigrated by a double way to the United States, either directly from 
Europe or from the north in remote times. The plant is indicated by Hooker 
in Iceland; by Martens, in Spitzbergen, Greenland, Iceland and Labrador; by 
Meyer, in Labrador; by Ledebour, in Siberia and Kamtschatka; by Watson 
(King’s Report), in the Uintah Mountains, in an altitude of 10,000 feet; by 
Parry, in the Rocky Mountains, and by Lapham, in Wisconsin. That shows 
that we can have the plant just as well from the north as from the east, where 
it probably came directly from Europe By the same double way we got, 
probably, five of our grasses, all acknowledged by Gray as indigenous: The Red 
Top (Agrostis vulgaris), the White Bent Grass (Agrostis alba), the Low Spear 
Grass (Poa annua), the Wire Grass (Poa compressa), and the Kentucky Blue 
Grass (Poa pratensis). The Barn-yard Grass (Panicum crista Galli) is a cos- 
mopolite, and occurs even in the deserts of Utah and Nevada. 
The Pigweed (Chenopodium album) and the Maple-leaved Goosefoot (Cheno- 
podium hybridum) are believed to be introduced species, but Watson (King’s 
Report) does concede them both to be indigenous. The first one is found from 
the Great Bear Lake to Nevada, and the other from Saskatchawan to the Wah- 
satch Mountains, both together in the Rocky Mountains of Colorado, in 10,000 
feet altitude. So the eastern states may have them just as well from the west 
as from Europe, or both ways. The same is good for two species of Amarantus, 
A. albus and A. retroflexus, which Watson declared as indigenous in the deserts 
beyond the Rocky Mountains. 
Lastly ought to be mentioned a number of plants that escape sometimes 
from gardens and other cultivated places, and of which some may be natural- 
ized in the course of time, such are: Silene Armeria, Hibiscus Trionum, Rosa 
rubiginosa, Centaurea Cyanus, Tanacetum vulgare, Lysimachia nummularia, 
Mentha viridis, Satureja hortensis, Ipomoea purpurea, Ipomoea nil, Lycium 
vulgare, Polygonum orientale, Fagopyrum esculentum, Euphorbia cyparissias, 
