Nature and Art, M.y 1, 18(7.] 
OUR BRITISH BUTTERFLIES. 
145 
interest, and therefore several French chemists and 
microscopists undertook the examination of the 
diseased and healthy worms. The result has been 
the discovery of the exciting cause of the disease. 
It has been found that the infected worms contained, 
scattered through their tissue, a number of minute 
bodies, probably spores or germinating particles of 
some low vegetable organism, and which have been 
termed pebrine corpuscles. They are of a peculiarly 
vibrating character, and if they happen to be present 
in the egg, they are sure to be found in the body 
of the future caterpillar. It was thought that they 
were gregarinida, but such a supposition is incorrect. 
That they are vegetable spores, which are capable 
of producing fermentation, and thus of decomposing 
the vital fluids of the silk-worm is clear, from an 
experiment made by M. Becliamp. M. Bechamp 
removed some of the fluid from a caterpillar in- 
fected with pebrine corpuscles, and placed it in a 
solution of sugar and water. The result was that 
alcoholic fermentation soon took place. Though 
not directly referring to microscopy, it may be 
mentioned that the source of these pebrine corpuscles 
has also been discovered by the French observer 
we have named who states that it is the wet or 
moist mulberry leaves with which the worms are 
fed. “ He took a number of worms from good 
healthy eggs, and divided them into two batches. 
One of these he fed with mulberry leaves, and to 
the other he gave leaves highly charged with 
moisture. He found that all those of the batch 
fed with dried leaves passed through their meta- 
morphoses ; whilst those in the other series 
perished.” * 
There is no subject which has of late attracted 
more attention from savants, especially in France, 
than that of spontaneous generation. In its investi- 
gation the microscope has been extensively used, 
and, according to both advocates and opponents of 
the theory, has furnished very valuable evidence. 
Besides M. Pouchet, the great supporter of the 
doctrine of heterogeny, the theory has found a new 
advocate in M. Donne, who, in a recent number of 
the Comptes Rendus of the French Academy, calls 
attention to certain experiments made by him, and 
which lie thinks establish beyond all question that 
organisms — living vegetable and animal forms — 
spring directly from decomposing animal matter. 
# Popular Science Review, April, p. 237. 
One of M. Donne’s experiments is extremely in- 
teresting. He took a hen’s egg, and having pierced 
it with a red-hot needle, and allowed a portion of 
the contents to escape, he lilled the space left by 
the evacuated contents with distilled water. Sealing 
up the aperture hermetically with wax, he left the 
egg exposed to a temperature of from 17° to 24 
of the centigrade thermometer* for about live 
days. He then removed the seal, and placing a 
drop of the egg-fluid under the microscope, he found 
it swarming with minute organisms termed vibrios. 
These are either animal or vegetable ; science has 
not determined which ; but they are certainly living 
creatures, and if they were not derived from the 
atmosphere, which generally contains their eggs in 
abundance, they must have proceeded directly from 
the decomposing matter of the egg. M. Donne’s 
facts are the most difficult to refute which have yet 
been put forward, and go nearer to destroy our 
belief in Harvey’s maxim, omne vivimi ex ovo, than 
any which have been yet presented to us. 
Adulteration is another subject concerning which 
the microscope provides us with useful information. 
It was frequently had recourse to by Dr. Hassall 
during the labours of the memorable Lancet 
Commission, and only the other day it was em- 
ployed for a similar purpose in France. M. T. 
Boussin has found that almost all the French soft- 
soaps, which should consist of potash and the acids 
of fat, are extensively adulterated with starch. 
Starch consists of extremely fine particles of an 
ovoid shape, and presenting a number of concentric 
coats. M. Boussin suspecting the presence of 
adulteration in the soaps examined by him, placed 
a small portion in the field of a microscope, under a 
power of a quarter of an inch focus. He soon per- 
ceived the starch granules in very lai’ge number, 
and presenting their characteristic shape, wrinklings, 
and series of consecutive layers, t 
We have already disposed of the space allotted 
to us in discussing the results recently achieved in 
the labours of microscopists. The second portion 
of our subject, therefore — that relating to the ad- 
vance made in the invention of microscopic ap- 
paratus and appliances — we must defer to our next 
number. 
* Equivalent to about 62° and 75° of Fahrenheit’s ther- 
mometer. 
f See the Chemical News, April 5th. 
OUR BRITISH BUTTERFLIES: 
Their Structure, Habits, History, and Foreign Relatives. 
By Arthur Gardiner Butler, F.Z.S. 
PART I. 
I N a former paper we have endeavoured to show 
how closely some foreign butterflies resemble 
our own : we now propose to point out how far 
some allied species excel ours in beauty of form and 
ii. 
colouration ; and as it appears to us that the study 
of British Butterflies, with regard to their structure, 
habits, &c., has been but imperfectly worked out, 
we shall strive to do something towards the attain- 
L 
