REGENERATION OF ANTENNZ—SCHMIT-JENSEN, 529 
these insects are reared together, for the specimens, which havejust cast 
their skin, become the victims of cannibalism, even if the food supply 
is kept fresh. Such was the case with the present lot. A number of 
the specimens were mutilated, being deprived more or less of their 
legs and antenne, and it was difficult to find a perfect specimen. 
One specimen especially attracted my notice. Its right antenna had 
been bitten off nearly to the base, and on the end of the remaining 
stump was a small Jump, which, to the unaided eye, appeared as a 
ball of antennal joints, which had grown together. As it would be 
of interest to observe how this formation would come through the 
moltings, this specimen was selected among others for a series of 
regeneration experiments, and its left front leg was amputated at the 
trochanter. At this date the larva was about 5 centimeters long; it 
was fed on fresh leaves of English ivy. 
On October 24, 1911, it molted. The cast skin was senfotihatinitells 
devoured Pinaceae The amputated leg was not regenerated, but 
the abnormal right antenna had undergone a very interesting change; 
the ‘‘ball”’ on the end of the antennal stump had developed into a 
distinct tarsus-like jomt with large empodium and with two weak 
but distinct claws. This peculiar formation was bluish green, which 
is the color of the blood of the insect, in contrast to the body and legs, 
which are light green. 
Figure 1 (pl. 1),is reproduced from a microphotograph, and shows the 
head of this specimen, enlarged 7 to 8 times. This photograph, as 
well as those for figures 2 and 6, was taken after the specimen had 
been strongly anesthetized with ether (anesthesia by chloroform 
often produces autotomy of the legs, if the specimen is touched even 
slightly). 
The considerable difference in the two antenne is very apparent 
from figure 1. On the abnormal antenna is found, nearest the head, 
the large basal jot, which has the shape of a cucumber seed, and 
which carries a short thin stem, consisting of four undoubted antennal 
joints. This stem carries an oblique, nearly oval joint, thickened at 
the apex and pointed toward the normal antenna. The claw- 
bearing joint is attached laterally to this irregular joint, which has 
several small bud-formed elevations. The claw-bearing joint is 
nearly spindle-shaped and carries apically a well developed empo- 
dium and a pair of weakly developed claws, which lie close to the 
dorsal surface of the empodium, one on each side of it. The normal 
relations, in size and position, of the empodium and the claws on the 
tarsus may be seen in figure 5. 
Comparison between the abnormal and the normal dattdnnd shows 
the different proportions of the parts. The right basal joint is some- 
what shorter than the left; the jomts which form the stem in the 
73176°—smM 1914——84 
