1912] Ephemeride Nymphs Heptagenia Inter punctata av 
specimen still remained helpless, disfigured, and unable to 
swim. All attempts to make it attach itself to a flat surface 
were of no avail, as the nymph would spring up like a stretched 
out hoop and fall to the bottom. When a small pebble was 
placed against the ventral surface of the insect, it was grasped 
and held tightly. Every day I gave it a trifle larger pebble and 
by the time of the next moulting, the nymph almost recovered 
its normal form. 
Undoubtedly the specimen experienced some difficulty from 
the beginning, in clinging to so small a pebble in such an unnat- 
ural condition, and yet the content derived through the contact 
with the pebble must have been more potent, for the nymph 
would curl itself about the pebble, getting as much of its body 
in contact with it as posslble, in spite of the fact that the body 
coiled itself into a complete ring. 
DEATH FEIGNING INSTINCT. 
The death feigning instinct 1s quite pronounced in May-fly 
nymphs when roughly handled out of water. It is rather diffi- 
cult, however, to make them feign death in water and when one 
is successful the feint lasts but a few minutes at the most, 
usually only a few seconds.* Holmes found that mature 
Ranatras will feign death very readily when taken out of the 
water and laid on the table, and that they will endure all sorts 
of maltreatment during the death-feint, even suffering their 
legs to be cut off one by one or their bodies cut in two without 
the least response. Most May-fly nymphs can be made to 
feign death by taking them out of the water and throwing them 
on the table, but the time of the feint varies widely in the differ- 
ent individuals, some feigning only a fraction of a minute, and 
others as long as fifteen minutes. The average death-feint 
lasts about two or three minutes, but it can be prolonged by 
stroking the nymph on the sternum or ventral part of the abdo- 
men. Under such conditions some specimens were observed 
to feign death on a very damp piece of cloth for a period longer 
than an hour. 
By placing nymphs with their backs against a rock, and the 
abdomen with the tracheal gills submerged under water, I have 
seen some of them feigning death as long as sixty-five minutes 
*Holmes, S. J. Death Feigning in Ranatra. The Journal of Comparative 
Neurology and Psychology, Volume 16, No. 3, pages 200-216, 1906. 
