NATURE 
489 
_ but is very sluggish, broad, more or less flattened, and, in 
_ fact, when full grown, looks like a small brown scale. 
The larve of Lepidoptera are familiar to us all, 
under the name of caterpillars. The insects of this 
order in their larval condilion are almost all phyto- 
phagous, and are very uniform both in structure and 
habits. The body is long and cylindrical, consisting of 
thirteen segments; the head is armed with powerful 
jaws ; the three following segments, the future prothorax, 
mesothorax, and metathorax, bear three pairs of simple 
articulated legs. Of the posterior segments, five also 
bear false or pro-legs, which .are short, unjointed, and 
provided with a number of hooklets. A caterpillar 
leads a dull and uneventful life ; it eats ravenously, and 
_ grows rapidly, casting its skin several times during the 
process, which generally lasts only a few weeks, though 
in some cases, as for instance the goat-moth, it extends 
over a period of two or three years, after which the larva 
changes into a quiescent pupa or chrysalis. 
; JoHN LUBBOCK 
(To Se continued.) 
ON THE STRUCTURE OF STRIPED MUS- 
CULAR FIBRE 
FA. ‘HIGHLY interesting paper on the above subject 
was read before the Royal Society on April 3, by 
Mr. E. A. Schafer, of University College. The muscle 
of the limbs of the large water-beetle formed the subject 
of the investigation, and it was examined immediately 
after removal from the living animal, without the addition 
of any reagent, to prevent the introduction of complica- 
tions. According to the author, a muscular fibre consists 
of a homogeneous ground substance, which appears at 
first sight to be formed of two distinct substances, one 
dim and the other bright, arranged in alternate discs at 
right angles to the direction of the fibre; and a vast 
number of minute rod-like bodies, imbedded in the proto- 
plasmic basis, having their axes coincident with that of 
the fibre itself. These are termed muscle.rods; in the 
muscle at absolute rest they are uniformly cylindrical, 
and produce the appearance of a simple longitudinal 
fibrillation in the fibre, with no transverse striping. But 
when in action these muscle-rods are terminated at each 
extremity by a knob, and are consequently dumb-bell 
shaped. It is these knobs which give the appearance of 
the line of dots which is always described as existing in 
the middle of each bright transverse band of the muscle 
fibre, whereas the dim one is that in which the shafts of 
the muscle-rods are imbedded. In contraction of the 
muscle, the heads of the rods become enlarged at the 
expense of the shafts, the extremities of each muscle-rod 
consequently approaching one another ; and the enlarged 
heads come nearer to their neighbours of the same series, 
and to those of the next series which meet them in the 
bright stripe, the line of dots now appearing as a dark 
transverse band with bright borders. As contraction 
proceeds the shaft of the muscle-rod tends to, and ulti- 
mately disappears, leaving an appearance of alternate 
dark and light stripes ; the former however are in this case 
_ dueto the enlarged juxtaposed extremities of the rods, the 
latter on the other hand being mainly due to the accumu- 
lation of the ground-substance in the intervals between 
their shafts. An examination of minute oil-globules 
imbedded in gelatine shows clearly that they give the 
appearance under the microscope of dark spots with a 
brilliant surrounding, and several side by side produce the 
effect of abright band. From many considerations it can 
be shown that the bright transverse bands in muscle are 
similarly produced by the jux'aposition of the rod-heads, 
among which are the following:—1. When the rod- 
heads are smaller the bright bands are narrower. 2. When | 
the rod-heads have become merged with the shafts in full 
contraction, the bright transverse stripes entirely dis- 
SSS EEE EEE EEE eee eee 
appear. 3. When in contraction the rod-heads enlarge 
and encroach on the shaft, their bright borders accompany 
them and encroach on the dim substance, so that at last 
all appearance of dimness becomes entirely obliterated, 
the bright borders becoming blended in the middle. 
4. The part of the muscle-rod where the head joins the 
shaft, is rendered indistinct by the brightness around the 
rod-head ; whereas if this brightness were inherent in the 
ground substance, this part of the rod would stand out 
all the darker by the contrast. 5. The appearance of a 
transverse section is corroborated ; for in this case the 
rod-heads are scen so close together that the optical effect 
of any one would become merged into those of its neigh- 
bours : consequently the whole of the intermediate sub- 
stance would appear bright; and this is actually found 
to be the case. 6, The fact that both the dim and the 
bright substance of resting muscle appear doubly re- 
fracting, would indicate that they are of the same nature. 
Mr. Schafer with polarised light has found that a//Z the 
ground-substance of the fibre is doubly refractive, the 
rods alone being singly refractive. He concludes the 
paper by offering a.conjecture as to the mode of muscular 
contraction, in which he is inclined to regard the ground- 
substance as the true contractile part, and the rods as 
elastic structures, merely serving to restore the fibre to its 
original length, 
NOTES 
A RUMOUR as to the fate of Sir Samuel and Lady Baker, 
of a kind similar to those which have ever and anon filled the 
air with reference to the undying Livingstone, appeared in the 
Times of Thursday last. At the end of last year, with his force 
dwindled down to 200 men, Sir Samuel had penetrated south 
until he had reached the territory of the chief of the tribes 
squatting near the great lakes, who had hitherto been friendly 
to the Egyptian government. His reception of Baker and his 
companions was however the reverse of friendly. Whatever the 
cause, a desperate conflict with the natives ensued, and after much 
hard fighting, Baker was compelled to retreat with but 30 out of 
his 200 men. It was with the utmost difficulty that the survivors 
succeeded in intrenching themselves in a small fort, whence to beat 
back further attacks. Such, according to report, was the state of 
matters at the end of last year. The present rumour is that Sir 
Samuel and Lady Baker having at last been compelled to sur- 
render, were immediately afterwards murdered. A telegram 
from H.M. Consul at Alexandria, dated the afternoon of last 
Thursday, announces that no intelligence of any sort respecting 
Sir Samuel and Lady Baker had been received by the Egyptian 
Government, or by any other, since March 5 last. <A telegram 
of April 19, from the Alexandria Daily News Correspondent 
states that the rumour seems to be utterly unfounded. We have, 
moreover, been assured by one who has the best opportunities of 
knowing, that no news has really been received, and that the 
reports about Sir Samuel are inventions: “ there is not,” he 
writes us, “a word of truth in them.” 
WE regret to announce that Baron Liebig’s illness, to which 
we referred last week, has terminated in death. The great 
chemist died on the 18th instant, aged nearly 70 years, having 
been born at Darmstadt on May 12, 1803. His funeral took 
place with great ceremony at Munich on the 21st. Wehope, in 
an early number, to be able to give a memoir of the late Baron, 
Ir is with the greatest regret that we announce the death, on 
the 2oth inst., after a long, and latterly, severe illness, of Dr. 
Bence Jones, Secretary to the Royal Institution, the efficiency of 
which hehas done much to promote. Dy. Jones was a distin- 
guished chemist, and among his;contributions to the advance- 
ment of science may be mentioned his Croonian Lectures on 
Matter and Force, Animal Chemistry in relation to Stomach ani 
