516 
NATURE 
[March 17, 1870 
: 
BOTANY 
Floating Leaves of Marsilea 
Pror. HILDEBRAND has noticed that ifa plant of Marsilea quad- 
rifolia (a species of the genus which furnishes Wardoo), is sunk 
beneath the surface of the water, so that all the leaves are more 
or less deeply covered, those leaves which are fully developed 
at the time of immersion, remain unchanged, while those which 
are not so far advanced, undergo a remarkable change; the 
petioles gradually lengthening in succession according to their posi- 
tion on the stem, and soon over-topping those which were already 
formed. At first the four leaflets do not increase, but they soon 
begin to enlarge, and by the time the surface of the water is 
reached, they exceed in size the ordinary leaves, forming a four- 
rayed star on the surface. While the petioles of the ordinary 
leaves are stiff, so that they stand erect out of the water, these 
floating leaves are weak and flexible, like those of water- 
lilies, allowing the leaf to maintain its position on the surface 
with the rise and fall of the water. Their upper surface is 
shining and coated with wax, so that the water flows off them. 
If immersed in deeper water, the petioles will lengthen still 
further, even to the extent of three feet. In these cases the 
formation of the organs of fructification appears to be suppressed. 
In the ordinary aérial leaves, stomata are found on both sides of 
the leaf in about equal numbers ; in the floating leaves, on the 
other hand, the under side is entirely destitute of stomata, while 
on the upper surface they are about three times as numerous as 
in the aérial leaves; thus resembling Mymphea, Hydrocharis, 
and other plants. (Botanische Zeitung.) 
Alternation of Generation in Fungi 
M. GaurieL River records in the Bulletin de la Société Bota- 
nique de France a remarkable illustration of this phenomenon in 
some very interesting observations on the ‘‘ rust ” of cereals. He 
finds that the Fungus which causes one of the common forms of this 
disease, Puccinia graminis, will not reproduce itself, but that if the 
spores are sown on the leaves of the common berberry, they give 
rise to the well-known orange spots of (cidium Berberidis, 
generally considered as a fungus belonging to an entirely different 
group. The spores of the @cidium, on the other hand, do not 
reproduce itself, but the Puccinia, thus furnishing a striking 
instance of alternation of generation. The connection of the 
berberry with the prevalence of rust in wheat was noticed by 
Sir Joseph Banks as long ago as 1806. In the commune of 
Genlis (Department of Cote d’Or) a railway company not long 
since planted a berberry hedge on one of its embankments; 
immediately the crops of wheat, rye, and barley in the neigh- 
bourhood became infested with rust. "The remonstrances of the 
farmers caused the appointment of a commissioner to inquire 
into the subject, who, after a full inquiry, reported that where- 
ever the berberry is planted the cereals are more or less at- 
tacked by rust; where they are absent the crops are free from 
disease, and that the planting of a single berberry bush is suffi- 
cient to produce the rust where it has never appeared before. 
PHM SITES 
Products of Respiration 
PETTENKOFER and Voir have been making some observations, 
by the help of their famous dog, on the products of respiration 
during starvation and during a diet entirely composed of fat. 
They find the most notable effect of the fatty food to be a diminution 
of the oxygen consumed. Thus in one series, on the 6th and roth 
days of a period during which nothing but water was taken, 
the oxygen consumed amounted to 358 and 302, the carbonic 
acid given off to 366, 289 grammes respectively. On the 2nd, 
3rd, and 8th days of a similar series the quantities were of 
oxygen consumed 371, 358, 335 ; of carbonic acid given off 380, 
358, 334 grammes. When, on the other hand, 100 grammes of 
fat were taken daily, the 8th and roth days of the series gave 
respectively 262, 226 grammes of oxygen consumed, 302, 312 
grammes of carbonic acid exhaled. (Zeitschrift fiir Biologie, 
bd. iii., p. 369.) 
In these observations Voit finds support of his views on the 
nutritive influence of fat, and bases on them an explanation of 
Bantingism. ‘To bring down a fatty body, he says, we must get 
it to take in a larger supply of oxygen. ‘This can best be done 
by cutting off all the fat and carbo-hydrates and increasing the 
quantity of proteids. The effect of increasing the proteids is to 
augment the metamorphosis taking place in the blood and 
diminish the storing up of material in the tissues in the shape — 
either of flesh or fat. The store of fat existing in the body is 
consequently more and more encroached upon, and in spite of © 
the great metamorphosis taking place in the circulation, the body 
continues to get lean. A yery long discussion on the modus 
operandi of fat as food (of which the above forms a small part 
only) will be found at p. 329. 
The same observers have also examined the respiratory products 
in the case of a man suffering from Leukaemia, a disease in 
which there is an undue abundance of white corpuscles and 
scantiness of the oxygen-bearing red ones. They find, however, 
no marked difference in the respiratory products; in amount 
these closely approximate the standard of health. (Ibid. p. 319.) 
G. Quincke on Specific Cohesion and Capillarity 
Constants 
Various bodies were formed into drops, which were allowed 
to fall on a platinum or porcelain plane; after they had ac- 
quired the temperature of the surrounding air, certain measure- 
ments were made of their dimensions. The square of the vertical 
distance in millimeters of the upper surface of the drop from the 
vertical element of its meridian curve is the constant of specific 
cohesion, from which, by a method of calculation stated by the 
author, the capillarity constant can be inferred. 
Fused substances of similar chemical composition, and at a 
temperature very near to their melting point, have the same 
specific cohesion. 
Water, carbonates, and sulphates in the liquid state have double 
the specific cohesion of mercury; the same is true for the nitrates, 
metallic chlorides, sugars, and fats; metallic iodides and bromides 
have only half the mercurial value. 
Lead, bismuth, and antimony have the same specific cohesion - 
as mercury; platinum, gold, silver, cadmium, tin, and copper 
twice that amount ; zinc, iron, and palladium thrice, and sodium 
six times the specific cohesion of mercury. 
PHYSIOLOGY | 
Microcephalous Children 
Dr. BUCHNER has measured lately the crania of two micro- 
cephalous children, and by way of comparison adds the cranial 
measure of his own healthy infant son. 
Helena Becker. 
Sophia S. W, Biichner. 
Age = 95 = =~ SOs years, 3 years. 3 years. 
Circumferen fj 5 : 
eed SS 3k inches, Rh. 16}inches. 204 inches. 
From eartoear . 6} ,, TO!" iiss 12) 5 
From root of 
nose to occipital 8 ,, LOX as; SiGe 56 
protuberance 
In both cases the size of head has apparently remained stationary 
from birth, and both children were born with closed foztanelles. 
One of the children is now exhibited at Darmstadt. Her 
height is 34 feet; she cannot speak, walk, or stand, or seize 
hold of anything ; in fact she is in a state of complete help- 
lessness, with involuntary action of bladder and rectum. The 
upper portion of her skull, not larger than a man’s fist, roof-like, 
flattened at the sides ; the absence of forehead, a long aquiline 
nose terminating in a sharp point, an exceedingly diminutive 
receding chin, and a mouth with irregularly set teeth, with — 
the orbital regions very prominent, give her quite an animal 
aspect. The mental phenomena are below zero; and the senses, 
though seemingly active, produce no ideas ; her look is staring, 
vacant, devoid of expression ; only bright shining objects and 
music attract her attention ;.she does not laugh but utters in- 
articulate animal sounds. Another characteristic feature is, that 
her limbs and head are subject to an involuntary unceasing 
agitation, like the reflex movements of a decapitated frog; she 
suffers also from a great want of sleep. 
Dr. OMANZA describes a method of registering photographi- 
cally the beats of the pulse. The apparatus essentially consists 
of a small inverted funnel, having a long narrow stem and a 
caoutchouc base. ‘This instrument is filled with mercury to a 
certain distance up the stem, and its base is applied to the heart 
or an artery; the oscillations of the mercurial column are then 
photographed by well-known processes. It is said that with this 
apparatus |the apparently single stroke of the pulse is shown to 
consist of three, or even four, in succession, 
