1890.] Psychology. 973 
the process of drawing is simple. My usual method is in the case of 
bisymmetrical insects to measure carefully with a pair of good dividers 
the length of the insect, transferring. the measurements to a piece of 
paper, and drawing a straight line between the two end points. Then 
measure the length and breadth of every part of half of the insect, 
and locate these points on one side of the line. When the outline of 
half the insect is satisfactory, trace it, straight line included, on the 
transfer paper. Now reverse the transfer paper, placing the traced 
outline on the opposite side of the straight line, and rub over it with 
some hard point,—the point of a lead pencil, for instance. Remove 
the transfer paper, and the outline of the whole insect appears. This 
completed outline is then transferred by means of tracing paper to the 
special process stipple paper, and the drawing proper is made with the 
wax crayon. Pen and ink is used occasionally to indicate fine hairs, 
etc. Many beginners make outlines in ink, where simple crayon 
outlines would be better. It is important to keep the black and white 
points distinct, not blending them by rubbing." 
To this it may be added that all drawings should be reduced about 
one-third or one-fourth, z. e., to two-thirds or three-fourths the size of 
the drawing. Theengraving should be done by a good establishment. 
It does not pay to have the cheap processes of zinc-etching, etc., tried 
on good drawings. Many engraving establishments return soft metal 
cuts, in which case they should be saved as originals and electrotypes 
made from them.—C. M. W. 
PSYCHOLOGY. 
Jastrow on a Writing Test.—In a paper entitled ** A Study in 
Mental Statistics," Prof. Jastrow describes the results of a mental test 
in which fifty students of a class in psychology, at the University of 
Wisconsin (twenty-five men and twenty-five women), took part. 
task consisted in writing 100 words as rapidly as possible. The mate- 
riàl thus collected was utilized to shed light upon (1) the similarity of 
our ideas and habits of thought, (2) the links that bind our ideas 
together, and (3) the time required for these processes. 
(1) The general tendency to regard one's mental habits and products 
- as singular and original, and consequently to look upon every evidence 
of similarity of thought as a strange coincidence, receives a set-back 
from the result of the present and similar studies, for it is found that 
Am. Nat.—October.—7. 
