THE 
QUEENSLAND PHILOSOPHICAL SOCIETY. 
(From the Queensland Guardian , November 21, 1866.) 
POISONOUS ANIMALS. 
The following paper was read before the 
Philosophical Society, by Dr. Bancroft, at its 
meeting on Monday, November 19, 1866 : — 
There are many interesting facts that de- 
serve further investigation respecting the 
poisonous effects produced by noxious animals 
found in this country. I select for description 
the common “ tick,” which abounds in some 
parts of the thickly wooded districts — the 
scrubs. It belongs to the Arachnida or 
spider class, — to which, also, belong scorpions, 
spiders, mites, the human itch insect, the scab 
insect of the sheep, and many other poisonous 
creatures. 
The ticks that live on the dog and sheep in 
Europe crawl upon those animals when in the 
woods ; they are not destructive to life, but 
the one here described is to our introduced 
animals very poisonous, and the dog and cat 
are frequently killed by it. The tick varies in 
size from the smallest point to a quarter of 
an inch, and when distended with blood is 
often half-an-inch long, and nearly of the shape 
of a castor oil seed. From this resemblance 
the castor oil seed was called by the Romans 
Ricinus (Eng. tick), and the castor oil plant is 
now called Ricinus communis. 
The ticks are found on men and animals 
after walking through tne scrubs, and in some 
parts they abound to such an extent that it 
becomes a serious matter to remain in their 
strongholds. Contact with an animal of large 
size is an event in the life of a tick not to be 
disregarded. Its carniverous propensities now 
come into vigorous action ; in a short time it 
penetrates the skin, sacrificing its powers of 
locomotion to enjoy a continuous feast on the 
blood of its victim. 
The tick generally seizes upon the soft 
folds of the skin — about the neck and 
ears of dogs, and in men, about the 
neck, groin, and armpit. In attaching them- 
selves to the skin, they produce little pam, 
and are rarely noticed j but shortly afterwards 
a small inflamed point results, which the un- 
informed mistake for a small boil. 
Persons familiar with the tick can tell by the 
peculiarity of the pain when the inflamed 
point is touched that he is suffering from a 
tick bite. He then seizes the tick between his 
nails, and plucks it off. 
How so snail an insect can attach itself 
with such force to the skin is understood by 
referring to the microscopic structure of its 
back. 
The beak, or penetrating organ, is a fiftieth 
of an inch long, and consists of two outer valves 
which form its sheath. The central body is 
conical, and covered with minute barbules 
pointing backwards — all arranged in rows of 
about twelve, and of these rows there are six ; so 
on this small organ we find upwards of seventy 
barbules. Applied to the sides of the penetrator 
are two finer instruments without barbules 
except at their points, where there are five. 
These organs I consider assist in penetration, 
by attaching themselves in the first instance 
so that the tick then has some support by 
which he can press forward the central pene- 
trator. 
The feet are not a little curious and consist 
of an oval elastic pad, to the margin of which 
wo find two fine booklets. By means of the 
barbules on the penetrator, the attachment 
becomes more or less permanent, and it would 
appear that the tick, once adherent cannot 
disconnect itself. That circumstance would 
probably occur in some instances by ulceration 
of the structure into which the tick had peno- 
