34 
POPULAR SCIENCE NEWS. 
[March, 1891, 
paste ; the upward-growing hyphae are to develop 
reproductive cells or spores. In other words, the 
part of the former is to provide for the mainte- 
nance of the individual plant; that of the latter, 
to secure the maintenance of the species. Thus 
we see in this simple vegetative organism a differ- 
entiation of parts for the carrying out of the two 
fundamental functions of life. 
We need notice further, in regard to the devel- 
opment of the mould plant, that the erect hyphae 
soon give oft" branches and that these branches 
come to bear spores. What happens is that the 
terminal points of the branches swell out into 
little balls, and that the necks of the balls elon- 
gate, swell, and so form other balls, the process 
continuing until rows of five or six are formed on 
each branch. These minute balls are, of course, 
spores. They finally fall off into the liquid, there 
to give rise to another generation; or, as com- 
monly happens, they are detached and borne 
away by currents of air, and the matter of their 
life or death then depends upon the kind of sub- 
stance they happen to lodge upon. That the 
spores of moulds float in all ordinary atmospheres 
is shown by the fact that these plants show them- 
selves upon any organic substance undergoing 
decay from which they can derive sustenance. 
And this brings us to uotice a radical physio- 
logical difference between the mould plant and 
the desmid described in the first paper. We saw 
that the latter took up food matter, in the form of 
simple inorganic compounds, from the air and 
water, and by the agency of its chlorophyl, or 
green coloring matter, elaborated them into highly 
complex energized compounds, by means of the 
sunlight. Now the mould has no chlorophyl, — 
its green color is due to another substance not 
related to chlorophyl, — and it can make no use of 
the energy of sunlight. It has no power to take 
inert inorganic compounds, like carbonic acid and 
water, and to cause radiant energy to build them 
up into complex products potent to nourish pro- 
toplasm. Therefore the mould plant must go to 
the organic world for food — that is to say, must 
appropriate material that has already stored up 
in it energy which the protoplasm of its cells can 
transfer to itself. 
The mould plant and all others of the group to 
which it belongs — namely, the Fungi — are, in fact, 
in the same relation to green plants as animals 
are. Green i)lants stand between the lifeless 
(inorganic) world and the animal kingdom, tak- 
ing things from the former and building them up 
into products which, as food matter, can sustain 
the latter. And the Fungi have the same depend- 
ent relation as the animals. But there is this dif- 
ference, that Fungi require that organic matter to 
serve them as food shall be in a state of decay. 
They never attach themselves to living bodies, 
but only to the matter of bodies (plant or animal) 
from which life has departed. Accordingly Fungi 
are distinguished from those plants which feed 
upon the living tissues of other plants, termed 
parasitic plants, by the designation saprophytes. 
Examples of parasitic plants are the dodder and 
mig.tletoe; and of saprophytic plants such com- 
mon Fungi as — besides moulds — mushrooms, toad- 
stools, and puff-balls. 
We have seen that the minute spores produced 
by the green mould are reproductive cells; each 
one of the half a hundred spores borne by a single 
plant is capable of giving rise to a new plant. 
But it is clear that this method of reproduction is 
not a sexual one, and we are therefore led to ex- 
pect, on the basis of our knowledge of the preva- 
lence of the sexual principle throughout the plant 
kingdom, as stated in the first paper, that Peni- 
cillium glaucum has still another way by which 
its species is perpetuated. Acting upon this in- 
ference, botanists have discovered within recent 
years, by the careful study of cultures of the 
plant, its sexual method of reproduction. What 
is observed is, that one of ithe erect hyphae length- 
ens and becomes coiled into a hollow spiral, and 
at the same time cross-partitions form dividing it 
into several cells. Meanwhile from below the 
spiral another branch grows up, and finally brings 
its extremity into contact with the end cell of the 
spiral. The adjacent cell walls then thin away, 
adinitting of a mingling of the protoplasm of the 
two parts. 'ITie ultimate result is the formation 
of a number of spores out of the protoplasm thus 
formed by union. It cannot be doubted that these 
spores have a potency different from that of the 
ordinary ones. The protoplasm derived from the 
spiral and that from the applied branch have simi- 
lar differences in respect to sexual character as 
that which exists between the protoplasm of an 
ovule (female cell) and that of a pollen grain 
(male cell) produced in the flower of one of the 
higher plants. 
Union College, Schenectady, N. Y. 
[Original In Populas Science News.] 
AN INTIMATE ENEMY. 
BY S. L. CLAYES. 
If the fly were possessed of a sense of humor it 
would surely find amusement in the manner in 
which its whole life bids defiance to man's social 
code. Hatched upon a heap of the most revolting 
filth, in whose midst the whole of its larva and 
pupa states are passed, and which will again serve 
as cradle and nursery for its own young, — un- 
abashed by its lowly origin, — it presumes, in its 
perfect fomi, not only to enter fearlessly houses, 
churches, palaces, and courts of justice, but pene- 
trates into their most sacred recesses, and actually 
assumes everywhere to take precedence of man 
himself. And this is not all. AVithout hesitation 
it trespasses upon the privacy of his table, his 
sleeping apartment, even his bath, and in each 
place seems more unbearably intrusive and self- 
asserting than in the last. It insists upon a first 
taste of his most costly and delicate plate. It 
sips from his cup before he has had time to raise 
it to his own lips. By its rushings, its buzzings, 
its bitings, and its ever-returning treadings with 
tickling feet upon the most sensitive portions of 
his person, it at times nearly succeeds in driving 
man to abandon that most cherished of all his 
possessions — his hearth and home. In an ancient 
Greek fable our enemy is made to say of himself : 
"It is well known what my pretensions are, and 
how justly they are founded : there is never a sac- 
rifice that is offered but I always taste the entrails 
— even before the gods themselves. I have a free 
admission at court, and can never want the king's 
ear, for I sometimes sit upon his shoulder. And 
then I eat and drink of the best of everything 
without having any occasion to work for my liv- 
ing. What life is to be compared to mine?" 
The fly family is so very large that it would be 
impossible to crowd even the names of its difter- 
ent varieties into the space which is permitted to 
my little sketch. Naturalists have already dis- 
covered more than eight hundred species, and 
some one or more of these many kinds are to be 
found in almost every part of the world. Wher- 
ever animal or vegetable life can flourish, where 
food can be found or eggs deposited, there a fly 
of some sort is sure to be. Meigen, who ranks as 
very high authority on European flies and their 
kindred, counts the species of the Old World as 
numbering about five hundred and fifty. Of these 
there are nearly one hundred kinds to be found 
in England alone. Here in America we have as 
many more. ITius, as Australia has her particu- 
lar breeds, you will perceive how formidable the 
list might grow. Indeed, Cuvier once said of it, 
" Well may the young student become alarmed." 
But, fortunately for us, there is no reason why 
we need to be appalled at its dimensions, for we 
have to do only with the common house-fly, or 
rather house-flies. Even among these, our well- 
known little housemates, there is a difference so 
marked that I dare say many of my readers — al- 
tliough they may not be versed in species — liave 
themselves noticed it. One of these, the Harpyia, 
is nearly as often inside our houses as even Musca 
domestica itself. It always enters at the approach 
of rain, and has a somewhat emphatic if not at- 
tractive way of calliug -our attention to its special 
personality. It rejoices in the possession of a 
particularly long, slender, and lancet-like probos- 
cis, which it gaily inserts by way of greeting into 
the person of some member of the family, just as 
soon as possible after its arriv.al in-doors. Its 
bite is of true severity, is often felt through more 
than one thickness of clothing, and generally 
draws blood. This amiable guest of ours carries 
her proboscis raised when the thirst for blood is 
upon her ; at other times she eitlier retracts it or 
wears it pressed ageinst her thorax. 
The proboscis of a fly, when examined through 
the microscope, shows great beauty, as well as a 
wonderful adaptation to the work which it has to 
perform. It is formed by a tube-like development 
of a portion of the under lip, and is composed of a 
soft, spongy, muscle-like mass. It is divided into 
sections, and can be doubled up, elongated, left 
exposed, or drawn within the head at the pleasure 
of the insect. A powerful muscle, shaped like a 
very minute hose, extends throughout its entire 
length, and it is lined with the finest imaginable 
hairs. ITie end terminates in two flattened lips, 
which possess a considerable power of suction. 
Through this tulie the fly obtains its food. When 
eating a drj^ sul)Stauce like sugar, it ejects upon it 
tiny drops of moisture, which cause it t» melt and 
fit it for being sucked up. This can be verified 
without resort to the microscope, by feeding a fly 
with some dark-colored jelly, and then placing 
him upon a lump of white sugar, which will soon 
become discolored in spots. A bit of newly- 
washed white linen may serve for the experiment 
perhaps even better than the sugar. The fly, 
which has certain epicurean tastes, seems to 
agree with Beau Brummel in thinking "there is 
nothing in nature equal to the perfume of clean 
linen," and also to believe that if well moistened 
this same perfume may be extracted and eaten. 
It would be useless to deny that this, our 
enemy, is the most tiresome and provoking of 
unbidden guests, and that his offences are legion. 
He defiles our choicest food, confections, and bev- 
erages, not only by tasting them with his lips, but 
by treading upon them with his feet, which may 
have been anywhere last. He deliberately and ma- 
liciously dances upon the bald head of the most 
august and highly-honored guest at our dinner- 
table, or on that of the most cherished member of 
the household. He buzzes in the ear of the orator 
at the acme of his pei-oration, or sharply stings 
the neck of the prima donna in the midst of her 
most elaborate trill. He alights upon the nose of 
the surgeon, disturbing brain and hand when a 
human lite is hanging upon their steadiness. He 
is guilty of every mischief, disgust, and diablerie 
to be found in the calendar; and he gives us in 
return — what? First, a continued and free aero- 
