1884. ] Scientific News. 1181 
SCIENTIFIC NEWS. 
— We have received a description, by Professor Alfred C. 
Haddon, of an apparatus for demonstrating systems of classifica- 
tion. What he proposes is very simple, merely consisting of a 
series of glass plates placed vertically over one another, leaving 
a small space between each, and a number of small movable 
blocks. The exact method for supporting the glass plates is of 
no consequence, and may be varied to any extent. The apparatus 
which he employs “consists of an oblong mahogany board, let 
into the corners of which are four brass sockets; into these are 
inserted four brass standards which are pierced with holes at reg- 
ular intervals in such a manner that the holes in each end-stand- 
ard are vis à vis with those of its fellow, and are at the same time 
parallel with those at the opposite end: Through these holes 
rass wires are inserted, and it is upon these that the glass plates 
rest. This apparatus has the advantage of being readily taken to 
pieces, and being quite portable. The names should be printed 
on paper, then cut out and pasted on two faces of oblong blocks 
of wood in such a manner that they can be read in a front view 
or by looking down vertically upon the apparatus. A makeshift 
may be constructed by bending a small oblong piece of cardboard 
toofwise and writing the name on one face of the anticlinal. The 
several blocks may be linked together in the same plane by pins 
placed either vertically or obliquely, and reaching to the upper 
plate. Any complicated system of linkage is thus possible. 
“In a classification of recent forms, each plate might represent a 
stage of differentiation, and the arrangement of the forms on that 
superficies would indicate their inter-relationships. The lower 
planes would naturally be chosen for the less differentiated types. 
An area on each plane could always be made by a colored line to 
represent some special modification. Degraded animals might be 
tinted, and a black pin slanting from the higher to the degenerate 
fm would graphically show that it was not an ascending type. 
Missing links between more or less widely separated, living ani- 
mals could be appropriately supplied by names within brackets. 
or phylogeny the arrangement would be somewhat similar 
except that each plate would represent some geologica orizon, 
e name of which would be ona block placed in one corner. 
and name in each geological epoch should be tinted in some 
oo color, so as to distinguish at a glance its precise 
zon. 
“rT 
ee e philosophical paleontologist arranges hie eg N pE 
ane so as to indicate the relations of each animal to those p 
