1963 ] Eisner , Hurst and Meinwald — Defense Mechanisms 109 
(3-5 cm. in length) whose ambulatory pace was measured (same tech- 
nique as with Chlaenius) yielded values ranging from 2.6 to 6.0 
cm./s. The distance that a given Abacion may be expected to cover 
unmolested after discharging is therefore considerably less than the 
100 m. one can expect from Chlaenius. But Abacion, with its two 
glands per most body segments, has a rather formidable secretory 
supply not easily depleted, particularly since its glands are likely to 
be called into action only a few at a time rather than all at once (at 
least so long as small predators are involved that inflict localized 
rather than generalized injury). Small arthropod predators, and ants 
in particular, are probably among the chief natural enemies of Abacion. 
Considering its rich glandular endowment, and the proven effectiveness 
of “death-feigning”, Abacion appears indeed to be a most admirably 
protected animal. 
b. Crotaphytus collaris (Say) 
Two tests were made, one with Chlaenius and one with Abacion. 
In the case of the millipede, the lizard eyed it almost continuously 
as it walked about the cage, but made no effort to seize it or even 
to approach it. One hesitates to attribute special significance to an 
isolated finding of this sort, but it should be mentioned that this 
particular lizard was confronted with no millipedes during its one 
year in captivity, and that its voraciousness at the time of the experi- 
ment was demonstrated by the readiness with which it caught and ate 
mealworms (larval Tenebrio molitor) . 
With the single Chlaenius the results were dramatically different. 
The lizard chased the beetle and caught it in its jaws, but instantly 
released it again, thereafter wiping its snout for several seconds in the 
substrate. Some secretion had evidently hit one eye, which remained 
closed for more than a minute. The beetle was uninjured (it smelled 
conspicuously of w-cresol when retrieved). The lizard showed no 
noticeable long range ill-effects. 
c. Cyanocitta cristata (Linnaeus) 
1. Versus Chlaenius. 
Three beetles were offered, one after the other, within a period 
of 30 minutes. The results were the same in each case. The bird 
descended from its perch, and quickly pecked the beetle to death. 
Except for an occasional brief but violent shaking of the head, the bird 
betrayed no signs of discomfort. There was no question that the beetle 
had sprayed: the phenolic odor was clearly apparent, even from 
outside the cage. 
