52 Notices respecting New Books. 
This mutation of skin resembles more that of the crustaceous 
animals than the insects, differing from the former in this, that 
every mutation brings a slight increase to the young Julus, and 
the successive mutations continue till it has finished growing. 
Previous to casting the old skin, which opens at the head above 
‘the eyes, the animal walks out of it in the new. The Julus is 
drowsy or torpid, and does not eat, a state which continues 
twenty-four hours, It appears that, like theCrustucea, the young 
Julus eats its old skin. In one of those ejected covers Dr. Savi 
found all the parts quite distinct, as the eyes, antennz, rings, 
legs, and, what is more extraordinary, the intestinal canal and 
the superficies of the trachea. This Julus also, like the crabs and 
shrimps, can reproduce its legs and antenne if destroyed. The 
stigmata and trachea were discovered at the junctures of the legs 
with the body, and immediately within the button-like juncture 
of the rings. The circumstance which led to this discovery of the 
position of the stigmata and trachea was in consequence of im- 
mersing these insects in olive oil to ascertain the duration of 
their life; when little air bubbles immediately appeared at the 
junction of every pair of legs. Hence it appears that the stig- 
mata and trachea pass along the under side of the insect in its 
whole length. Lastly, this animalis furnished with a fetid liquor, 
which it can secrete occasionally, and which has some singular 
properties. It was well known that these insects have a very 
offensive smell, but it remained for Dr. Savi to discover its cause. 
If this Julus be irritated, by touching it suddenly and with suffi- 
cient force to intimidate it, immediately a very pungent and dis- 
agreeable odour is emitted. It appears that on each side of the 
animal there is a line of pores, one of which is in each ring, 
through which a yellow fcetid liquor transpires, These pores 
have been confounded with the stigmata, but they are in fact 
merely the orifices of the little bladders which contain this stink- 
ing liquid. Among the singular properties of this yellow fluid is 
that of staining the skin on which it is allowed to dry, of a bright 
red, similar to that produced by muriate of mercury or muriate 
of gold, and the colour is indestructible, and can only be removed 
by time. This liquor removed from its reservoirs, in a short 
time, when viewed with a microscope, assumes the form of very 
limpid octohedral crystals ; its gravity is similar to that of olive oil; 
itis of a reddish yellow colour; its smell is strong, pungent, and 
to some similar to that of chlorine; its taste is very caustic; and 
produces a sensation on the tongue like the prick of a needle ; 
it unites with water, but much better and more eagerly with 
spirit of wine; the latter did not renew the colour of paper 
stained with turnsole and reddened with acid: but a piece of pa- 
per coloured with turnsole and exposed to this yellow ee 
after 
