732 
Supplement to the " Tropical Agriculturist." [April 1, 1901. 
various but not all kinds of Flies) in the hardened 
skin of the maggot, which may he called a 
"Fly-case"; aiid in some (as with Plant Bugs, 
Aphides or Green Fly, Grasshoppers, and some 
others) this state of pupa is an active one, in 
which they move and feed and resemble the per- 
fect^ insecf, excepting in having more or le>s 
rudimentary wings or wing-cases. When the 
time for development hns come, the pupa (if it is 
one of the active forms, as of a Grasshopper, for 
instance) may be seen looking heavy and stupid ; 
presently the skin of the back splits lengthwise, 
and through the opening the perfect insect slowly 
makes its way out of the pupal skin, carefully 
drawing one limb after atiother from its precisely- 
fitting case, the longhind legs the last, till (in the 
instance observed, in twenty minutes) the perfect 
Grasshopper stands by the side of the film of its 
former self. Flies press out one end of the fly- 
case, or crack it open, or leave the sheaths cf the 
limbs and body beliind, and Beetles and Wasps 
cast the film from their limbs ; Butterflies and 
Moths crack open the chrysalis-case, and after a 
short time'(during which the wings that had lain 
nndevelopied are expanding) they appear of tlieir 
full size. The insect is now fully formed ; it will 
grow no more; its internal, as well as external, 
structure is complete ; and it is what is known 
scientifically as the imago. 
Imngo (Beetle, Butterfly, Wasp, Fly, &c.) This 
is defined as an animal formed of a series of 
thirteen rings or segments, breathing by means of 
tubes (tracheae) which convey the air from pores in 
the sides tliroughout the system, and divided into 
three chief portions. Of tliese the first is the head, 
furnished with horns (antennEe), a mouth (differing 
Tery much in form in different kinds of insects), 
large compound eyes (which consist of many small 
ones formed into a convex mass on each side of 
the head), and frequently two or three simple eyes 
on the top. 
The second portion (called the thorax, or some- 
times the "trunk") is formed of three rings 
bearing a pair of legs attached to each, and liaving 
usually a pair of wings on the second and third of 
the rings; but sometimes the wings are wanting, 
sometimes there is only one pair. 
The third portion (called the abdomen) is formed 
of the remaining nine rings, and contains the 
organs of reproduction and most of those of 
digestion. Insects in this perfect state are of two 
sexes, male and female ; in s^ime instances (as 
with Wasps and some others) there are imper- 
fectly-developed females known as "penters." 
After the insect — whether Beetle, Butterfly, Fly, 
or other kind — has come from its chrysalis or fly- 
case (that is, from the pupa), and its limbs have 
expanded, it is complete, and its remaining work 
is to support life until it has propagated its 
species. Usually pairing soon takes place, and 
the male dies ; but the female has great tenacity 
of life until she has laid her eggs. 
The length of life, however, is various ; in some 
ii:stances a few days, or even hours, is the extent; 
in others the insects " hybernate," that is, find 
some shelter in which they pass the winter, and 
from whicli they reappear with the return of 
warmth and sunshine, 
INOCULATION AGAINST EINDEEPEST. 
From Dr. Alfred Lingard, m.b., m.s., d p.h.. 
Imperial Bacteriologist— To the Secretary to the 
Director-General. India Medical Service— (No. 
8, dated iiukhtesar, Naiui Tal Districf, the 5th 
January 1901.) 
As desired by his Honour the Lieutenant- 
Governor of these Provinces during his visit to 
Mukhtesar in October-November last to put for- 
ward a concise statement of success obtained with 
serum inoculations and modes of its operation, 
with a view to give it publicity and persuade the 
leading zemindars and talukdars to give prompt 
information concerning outbreaks of rinderpest, 
so that they may Have their cattle inoculated 
before its ravages be felt, I have tlie honour to 
summarize in the following paragraphs the results 
obtained up to date, and request you to be good 
enough to submit this letter to the Chief Secretary 
to the Government of the North-West Provinces 
and Oudh : — 
Serum Simultaneous Method. — This method, 
which has been very widely adopted in South 
Africa with most encouraging results, consists in 
injecting a small dose of protective serum on one 
side of the animal's body, and at the same time a 
small dose of virulent rinderpest blood on the 
opposite side. A mild form of the disease is 
produced in 90 per cent of the animals, with a loss 
only of one-half per cent and with the production 
of a permanent immunity, while the other 10 per 
cent are also protected for some months, even 
though they fail to re-act to the inoculation. Iti 
this connection I would point out tliat when a 
totally unprotected animal is subcutaueously 
inoculated with the most virulent blood, it shows 
no symptoms of disease previous to the ord, 4th 
or .5th day following inoculation, and then only 
does the temperature begin to rise. It is not until 
at least three days later, viz., the 6th, 7th to 8th 
day that any symptoms of rinderpest become 
manifest. Tlierefore, in practical field inoculationa 
it has to be first ascertained whether the disease is 
already incubating in the animals about to be 
injculated, as in such cases the simultaneous 
method of inoculation should not be employed, but 
serum alone injected in large quantities should 
diarrhoea not yet have supervened. If this latter 
symptom should have already made its appearance 
nothing can save the affected animal. 
Experi7nents in the Laboratory. — The experi- 
ments carried out with the above mentioned 
method in this Laboratory prove that the animals 
which ahow temperature reactions with fairly 
marked symptoms are immuned for upwards of 
one year, and there is no reason to doubt that 
it will last for a much longer time, if not for the 
life of the animals. On the other hand, the 
animals showing no temperature reaction or 
symptoms of the disease, partly due to the large 
doses of serum us^, may wear off their immunity 
earlier than those which reached to the simultane- 
ous method, and this difficulty can be got over by 
reinoculating those animals, which have not 
reached within a week or ten days of the 
simultaneous injection with a second dose of from 
1 to 10 c,c. of virulent blood, 
