1876.] Are Potato Bugs Poisonous ? 205 
article on the. growth of the horns of the prong buck, in the 
NATURALIST, volume ii., page 131, and find some differences be- 
tween his observations and mine, from which we may infer the 
want of exact uniformity not only in the structure but in the 
progress of the growth of the horn. The section of the horn 
shown in Figure 12 shows a core differing in both form and ex- 
tent from any I have seen. I have never met one where the 
core extended above the prong. 
ARE POTATO BUGS POISONOUS?! 
BY AUG. R. GROTE AND ADOLPH KAYSER. 
A STATEMENT of the poisoning qualities of the Doryphora 
AA decemlineata, or potato bug, has repeatedly been made in pub- 
lic prints, and notably in the Seventh Report on the Insects of 
Missouri by Professor C. V. Riley. Itis claimed that after coming 
m contact with the bugs, or inhaling the steam or smoke produced 
by boiling or burning them, persons have exhibited various symp- 
toms of cutaneous or nervous disease. 
To investigate the matter, a quantity of the bugs collected from 
fields near Buffalo, where no arsenic had been used, was submit- 
ted to distillation with salt water, so as to allow of an increased 
temperature. Under this process, about four ounces of liquid were 
procured from one quart measure of the insects. This liquid was 
perfectly clear, and emitted a highly offensive smell ; it proved 
of alkaline reaction on account of the presence of a certain quan- 
tity of free ammonia and carbonate of ammonia. 
_ Again, an equal quantity of the bugs was used to prepare a 
tincture made as follows: Absolute and chemically pure alcohol 
was condensed upon the live bugs; after a digestion of twenty- 
four hours the alcohol was evaporated at a gentle heat. The 
tincture so obtained had a decidedly acid reaction, was brown in 
color, and was not disagreeable in smell. 
To ascertain the effect on the animal system of the liquid and 
the tincture above described, a number of frogs were procured for 
the experiment. About one half cubic centimetre of the liquid 
and the tincture each was introduced separately into the stomach. 
Neither the liquid nor the tincture produced any apparent effects. 
he vivacity of the frogs so treated continued unimpaired, not- 
withstanding the complete retention of the doses. Again, two 
1 We 
Read at the Detroit Meeting of the American Association for the Advancement 
t Science, 1875, 
