Many insects, particularly beetles, frequently escape their enemies by feigning death. Whether this behavior is an instinctive ruse or a genuine paralysis induced by something akin to fright we do not know, but it is doubtless of considerable value to the insect. Some butterflies have been known to play possum when in a tight place. _Vanessa cardui_, known as the Painted Lady, sometimes closes its wings, folds its legs close to the body, and falls motionless to the ground. Usually it is lost in the weeds or grasses, but even if found and picked up it often allows itself to be handled without any sign of life. Similar behavior has been reported in _Satyrus alope_, the Wood-nymph butterfly. Transcriber’s Notes In the Table of Contents, the page number for Chapter VI. has been corrected from 34 to 38. Page 11: Changed “Fritz Muller” to “Fritz Müller”. Page 16: In the illustration caption for Fig. I, “9. rectum, 10” was replaced with “9. rectum; 10”. Page 17: Changed “slender Malphighian tubules” to “slender Malpighian tubules”. Page 24: Changed “a reddish-brown color.” to “a reddish brown color.”. Page 25: Changed “far from the eggshell” to “far from the egg-shell”. Page 28: Added a missing “ before “6:00 p. m.”. Page 34 & 38: Changed “Hesperidae” to “Hesperiidae”. Page 48: Changed “ajax). a typical representative” to “ajax), a typical representative”. Changed “A egg” to “A, egg”. Page 58: Changed “green or light colored trees” to “green or light-colored trees”. Page 64: Changed “Wood-nymph butterfly,” to “Wood-nymph butterfly.”