^.^.Q N OtCS • 
both the animals and plants of the shores were probably derived 
from pelagic ancestors. 
Prof. A. W. Rucker, F.R.S., from an investigation of liquid 
films, arrives at the conclusion that the diameter of a molecule 
is considerably less than 2Xio~ 6 millimetres. 
We must hope that the Platypus will not be extirpated before 
its life-history has been completely worked out. Mr. Caldwell 
is searching for them, and has obtained in six weeks 500 spe- 
cimens. 
Dr. Aurivillius finds that the uniformity of the Ardlic fauna 
becomes more striking as we approach the Pole, but that three 
subdivisions are manifest, — the Scandinavian, the Asiatic, and 
the American. 
M. Felix Lucas, in a recent study on the radiations of incan- 
descent carbons, shows that the eledtric arc-light decreases in 
luminosity if the eledtric intensity or the temperature are carried 
beyond a certain limit. The radiations become first red, then 
white, and finally pass into the ultra-violet, where they no longer 
adt upon the human sight. 
V. Horsley, F.R.C.S., in a ledture delivered at the Royal Insti- 
tution on the “ Motor-Centres of the Brain and the Mechanism 
of the Will,” showed that as a rule both cerebral hemispheres are 
engaged at once in receiving and considering one idea ; that 
under no circumstances can two ideas either be considered or 
adted upon attentively at the same moment ; that the brain is a 
single instrument, and that our idea of our being single indivi- 
duals is due entirely to this single adtion of the brain. 
Mr. J. S. Kingsley has revised the inter-relationships of the 
arthropods. He finds that the arachnids are more closely allied 
to the crustaceans than to the hexapods and myriapods, with 
which they are usually classed. The arachnids and the hexapods 
have little in common, and the diviston Tracheata is artificial 
and not natural. 
“ Light ” says “ The limitation at present placed on natural 
laws must be relaxed.” 
Holland, it seems, is blessed with a Society for the Prevention 
of Cruelty to Animals, which body has petitioned the Government 
to introduce the restridlions on physiological experiments drawn 
up by the Prussian authorities, — restrictions not so bad as those 
in force in this country, but which certainly concede too much. 
A new form of Psychography has made its appearance, to 
which we call the special attention of conjurors and exposers. 
A blank sheet of paper and a clean pen nib are laid between two 
slates, and on the upper slate is placed a heavy inkstand. After 
a short time the upper slate is lifted off, when the paper is found 
covered with writing and the pen wet with ink. Who will solve 
this riddle ? 
