wild peas; matrimony vine is left to grow awhile among plants of bittersweet, ground cherry, horse-nettle and buffalo bur; the Oswego tea
shies its rootstocks all about and many appear and remain for a time with peppermint, spearmint, sage, origanum and motherwort; wormwood visits ox-eye daisy and the two agree well together; Canadian golden-rod creeps into plats of low-land grasses, sedges, wild asters and artichokes; the enterprising dandelion 
Fig. 6. A Cross section much enlarged of a Bladder-like Trap which catches worms. (After Darwin.) is found in plats of hawkweed, chicory, wild lettuce sowthistle, and is often overlooked; and squaw-weed finds a welcome with sweet-colt's-foot.
An Iris that imitates a Rattlesnake.—In portions of Washington rattlesnakes are very abundant, and are much dreaded by cattle and horses which graze large portions of the state.
In this region grow large quantites of Iris Missouriensis and when ripe the rattle of the seed in the pods closely resembles the rattle of the snake. Grazing animals invariably step back after hitting these pods, and thus the green leaves of the plants are spared to work for future crops of seeds.
For this observation I am indebted to Matt Crosby, of the U. S. Bureau of Forestry.
