1883. ] Microscopy. 1311 
‘examine the perfected form and try to understand the machine 
by a series of eliminations. He first, by way of explaining his 
method, eliminates the improvements on the steam engine until 
he gets us back to a savage man blowing through a hollow reed 
that nature supplied. This was the starting point of invention, a 
purely human characteristic. The author then applies his 
‘method to bows and arrows, stone implements, etc., and is brought 
‘to the following conclusion: 
“TIt is clear that neither to Professor Dawkins and Professor 
Gaudry, nor to Mr. Grant Allen, is it hard to imagine that a crea- 
ture, inferior to man both in physical and mental structure, may 
have made such progress in art as to be able to work so difficult 
a material as flint, and to have developed such wants as to call 
for the practice of that art. All lose sight of the nature of art 
and the laws of human progress, and they indicate a conception 
of art prior to man, but an inability to conceive of man as exist- 
ing without a certain degree of progress in art. It would seem 
to them that the first human creature, whatever his origin, must 
have signalized his advent and perpetuated his memory literally 
‘ Monumentum aere perennius,’ 
by instantly, without preparation or conscious need, chipping out 
tools of flint. The quotation from Lucretius, : 
‘ Arma antiqua manus, ungues, dentes fuere, 
Et lapides, et item sylvarum fragmina rami; 
is misapplied by archæologists. Lapides does not mean flaked 
or polished stone any more than /ragmina ramı means dressed 
timber.” 
The author traces back of the rudest wrought stone, an age of 
wood, and other perishable materials, and anterior to that the 
age without invention. 
MICROSCOPY.’ 
RECENT IMPROVEMENTS IN SECTION-cuTTING.— In sectioning 
objects imbedded in paraffine, the knife is generally fixed, by a 
clamp, more or less obliquely to the carrier, and the sections al- 
most invariably roll. The rolling of the sections, which is 
caused by the bevel given to the cutting edge of the knife in sharp- 
ening it, besides leading to difficulties of manipulation in the pro- 
cess of mounting, often injures or completely ruins the sections. 
any efforts have been made to find some convenient means n 
preventing the rolling, and very recently successful methods an 
instruments have been devised to meet the difficulty. In pres 
knives I have found places where the edge was SO thin - the 
bevel appeared wholly wanting. Such portions of the kni e ae 
ally cut without causing the sections to roll; and this fact mig 
1 Edited by Dr, C. O. WHITMAN, Mus. Comparative Zoology, Cambridge, Mass. — 
