April 1, 1901.J Supplement to the " Tropical Agriculturist." 
731 
ists, chemist?, brewers, dairymen, agriculturists, 
tobacco manufacturers, tanners, and others are 
engaged in unravelling the mysteries of this subject 
in combating disease and prosecuting important 
manufactures. Some of the organisms which 
gave it its name were seen as long ago as 1675 — 
when Anton Leeuwenhoeck, a Dutch philosopher, 
not only made his microscope — a simple one — but 
applied it to such good purpose, that he discovered 
and described organisms which are now known as 
bacteria, bacilli, spirilla, and micrococci. He 
called them animalculae, but he failed to discover 
their object in nature. Subsequently original 
research was conducted by Muller, Needham, 
Spallanzani, Schwann, and Davaine, The real 
initiation of the science dates its birth to Louis 
Pasteur's classic lesearches upon fermentation. 
The question of spontaneous generation and its 
obscure origin had occupied the attention of great 
minds, including Liebig. His masterly essay on 
fermentation with his chemical theory received a 
rude shock when Pasteur gave forth his startling- 
proclamation in I860- " No fermentation without 
germ life." Robert Koch gave the science a 
lasting stimulus in 1882 by the discovery of the 
tubercle bacillus. Baron Lister, the brilliant 
surgeon, expressly thanked Pasteur for having 
given him the only principle which could have 
conducted the antiseptic system of surgery to a 
successful issue, and through which he is justly 
accredited with having saved more lives than were 
lost in the Franco-German war. Owing to the 
prominence given to bacteriology in mediciue and 
surgery, a belief has been engendered that germs 
are only associated with these sciences; but the 
army of earnest workers noW'engaged in the elu- 
cidation of their life history proves that the ubi- 
quitous microbe is omnipresent. We know now 
without it the world becomes uninha1)itable. In 
air, water, and soil we find it busily engaged 
in varied forms on nature's phenomena. 
To classify them into four great groups. First, 
the useful organisms. — The application of these 
to the arts and manufactures are daily becoming 
better defined, and are exerting a wouderfui in- 
fluence. In commercial life, we find the correct 
fermentation of wines and beers, and all the 
" diseases " to which these beverages are liable 
are due to microbes. The successful development 
of flavor in butter and the ripening of cheese, the 
flavoring of tobacco, the curing of opium, the 
manufacture of Indigo, the tanning of leather, the 
production of yeast for bread-making, " retting " 
in the jute and linen trades, and other iirocesses 
depend upon the use of the most desirable forms 
of these useful minute organisms ; the agricul- 
turalist in the nitrification of his soil, the reduc- 
tion of nitrogenous manures to a condition in 
which they can be utilised by crops, the sprouting 
of his seeds, and the success of his hay-stack and 
silo, is dependent upon the behavior of friendly 
bacteria. Second, the putrefaction of hostile 
bacterias. — In this section we find the putrefactive 
organisms associated with filth and decomposition. 
They habitually flourish iu darkness, organic matter 
w*iether it be a dead body or vegetable material is 
reduced by them to original constituents or 
elements. By this invasion, they interfere with 
the progress of useful processes, check suitable 
fermentations and changes, impart false flavors 
and aromas, and interfere with the functions of the 
desirable organisms. Third, the pathogenic or 
disease-producing micro-organisms.- -With this 
large and influential section we find eminent 
scientists and medical men have prosecuted the 
most profound researches through the instrumen- 
tality of which we find pathogenic germs are res- 
ponsible for such diseases as tuberculosis (con- 
sumption), small-pox, diphtheria, typhoid fever, 
measles, cholera, hydrophobia (lock-jaw), anthrax] 
and bubonic plague. Fourth, the unknown 
families of bacteria.-— We are cognisant that there 
are numberless species of organisms distributed 
throughout the world of life whose identity and 
functions are not yet discovered. So far, only 
about 700 species have been isolated, named, and 
their life histories and characteristics recorded. 
To attempt to give an adequate conception of 
the vast and ramifying influences exerted by 
bacteria would occupy too much space, I must 
therefore confine myself to the subject, as it effects 
the dairying industry,— T^e Station, Farm and 
Dairy. 
iTo be concluded.) 
— ♦> . 
INTEODUCTION TO ENTOMOLOGY. 
(Miss Elranor A. Obmerod.) 
Pupa {Chrysalis).— ix, is much to be regretted 
that we have no generally-adopted word, except- 
ing " chrysalis'' (which is commonly used in th« 
case of Butterflies or Moths), to describe the 
second stage of insect life in which it is changing 
from the state of larva to that of the complete 
insect. 
Whilst in this condition it is for the most part 
without power cf feeding and perfectly inactire, 
lying (as in the case of Beetles, — the common 
Cockchafer for instance,— Bees and Wasps, and 
some others) with limbs in sheaths folded beneath 
the breast and body, or (as with Butterflies and 
Moths) protected by a hardened coating secreted by 
the pores of the creature within, when it casts its 
last larval skin. The method of this change may 
be easily observed in the case of the caterpillar of 
the Peacock Butterfly, which fastens itself by the 
tail, and then (after its black and silver-spotted 
skin has cracked) by infinite wriggling and 
struggling passes this cast-off skin backward, till 
it is pressed together at the tip of the tail, 
and the creature from within appears in its 
new form as a bright green chrysalis or pupn. 
It is covered with a moist gummy exudation, 
which quickly hardens and forms a protecting 
coat, and in due time (if left unharmed) the 
butterfly inside would crack through this and 
appear from within the case ; but if it is wished 
to observe that the beginning of the chang-. to 
the Butterfly form has taken place already, one oi' 
these chrysalids may be dropped into a little warm 
turpentine, or turpentine and Canada balsam, 
directly the caterpillar skin has been cast ; this 
will soften the gummy coating just mentioned, 
and the limbs of the future Butterfly will be seen. 
In some cases the change takes place (as with 
