SCIENTIFIC SUMMARY. 
219 
is taken from a recent number of Zebender’s 11 Monatsblatt ” of an 
experiment of Listing, who has already done so much in physiological 
optics. It brings out stereoscopic effect with only one picture, which 
consists of figures arranged in a peculiar way, and seen with vertical 
double images. The simplest experiment is to view two lines cross- 
ing each other at an angle of about 30°, with a prism 
of 4° or 5°, its base vertical before one eye. No effort 
must be made to correct the vertical diplopia. If the prism 
be put before the left eye, its base upward, the line BB' 
seems nearer to the eye than A A 7 . If the prism be turned 
with its base downward, and before the same eye, the line 
A A' seems nearer, and B B' more remote. It is found that 
with the base downward the prism must be weaker than 
when turned with the base upward. In gaining the effect by 
prisms so weak as these, no double vision is produced except 
for horizontal lines — the oblique lines appear to be only two. 
The same phenomenon may be produced in a common stereoscope by having 
two similar figures, and pushing one alternately up and down* Two rows 
of the same letters are arranged on a page like the limbs of the letter X, 
and viewed as above stated with a vertically deflecting prism ; a sudden 
removal of one now takes place to a considerable depth, while this appear- 
ance is at once reversed on turning the prism around 180°. These curious 
effects can be best produced and understood by means of the diagrams 
accompanying the article. 
ZOOLOGY AND COMPARATIVE ANATOMY. 
Remarks on Transcendentalism by a former Transcendentalist . — In his 
annual address as President of the Royal Microscopical Society, Dr. 
Kitchen Parker, F.R.S., made some observations on the transcendentalists 
and their school which we think of importance. Thirty years ago, said 
Dr. Parker, his favourite author in these matters was Sir Charles Bell, a 
good type of the Paley or Fitness school. Such good reverential men 
loved to trace the handiwork of an infinitely clever Contriver , who brought 
organisms into being in a moment — monads or whales — the plan of each 
having been perfected beforehand by a mode of thought peculiarly human. 
Looking from another standpoint, and yet reverent as they, he has no 
quarrel, even now, with this school. They but saw and understood things 
in an ex parte manner, pleased with a fitness, delighted with a plan. There 
are deeper meanings than these in the vertebrate organisation 5 and as early 
as 1790 the great poet and morphologist, Goethe, began to get some glimmer- 
ings of a gorgeous morphological science unimagined by earlier observers 
and limited thinkers. In 1807 Lorenz Oken took up, worked out in his 
peculiar way, and went somehwat mad upon this most fascinating subject. 
He had several disciples, and the greatest of these was our own country- 
man, Richard Owen. “ I could almost have wished,” said Dr. Parker , u that 
the ‘transcendentalism ’ which grew out of these oblique giimpses, partial 
and fitful, in the dawn of a new era of biological science, had never reached 
