508 TRANSACTIONS OF SECTION D. 
vision is a condition of self-motility. Those individuals and types not 
securing the better vision are those excluded. The difficulties of creating 
the eye were so great that the unfit were usually those visually unfit. 
Ascent of types to fuller or higher function is measured and also largely 
caused by the slow approach of the visual axes from extreme divergence to 
the parallelism of Simiae and Homo, fighting-power and individualism 
proceeding pari passu with every approach to parallelism of the visual axes. 
A still more profound visual difficulty was overcome when it was found 
visually possible to guide and render habitual the change from horizontality 
of the animal body to verticality, partly effected in the Marsupialia and 
the Simiae, but successful in Homo. It was plainly impossible to create 
visual organs fitted equally well to serve animals at once horizontal and 
vertical ; even the intermediate or 45° animals, as the kangaroo, are zoologic 
failures. With the verticality of Homo severe labour was thrown upon the 
lumbar portion of the spinal column, but the influence of the ocular function 
of civilisation was required to produce the 80 per cent. of cases, among our 
educated classes, of lateral spinal curvature. With Homo came early the 
use of the hands as manipulative tools, the development of righthandedness 
and lefthandedness, the formation of language, and the location of the 
cerebral centres of righthandedness and speech in one cerebral hemisphere. 
Inevitable was also the development of righteyedness governing righthanded- 
ness, and of lefteyedness in lefthandedness. With the high differentiation 
and perfection of visual function in vertical man arose the necessity of the 
fifteen shading mechanisms of the retina upon which its greatest sensitive- 
ness depends. One of the most necessary of the shading devices is the 
placing of the border of the upper lid across the cornea at the upper edge of 
the pupil, whence arises astigmatism, a source of one of the most formidable 
of the ills of humanity. Direct and indirect consequences are the functional 
diseases seemingly of cerebral, digestional, and neurological nature, but 
really constituting the chiefest cause of exclusion of affected individuals 
from the evoluting phylum. The cerebrum is the inherited average of all 
past experience with approximately perfect visual images. When a highly 
variant individual stimulus comes in collision with this massive inheritance 
of the normal past, the individual and his morbidity must both be re-fused 
-—unless it be normalised artificially—-as is possible in this case, 
TUESDAY, AUGUST 31. 
The following Papers were read and Resolutions passed :— 
1. On the Distribution of the Rotifera. 
By Cuartes F. Rousssiet, F.R.M.S. 
The results of recent investigations point more and more to the fact that 
the Rotifera enjoy a cosmopolitan distribution which is not limited to con- 
tinents, but extends to all places on the surface of the earth where suitable 
conditions prevail. | Wherever search has extended in Europe, America, 
Africa, India, China, Australia, and even the North and South Polar 
regions, the same genera, and even species, have been met with, and it is not 
possible to speak of any typical or peculiar Rotatorian fauna for any con- 
tinent, zone or region. 
It is true that some species have so far been found in one locality only, 
but that must be attributed to the fact that no country has as yet been 
thoroughly explored. The greatest number of species are known from 
Europe, and in particular from England, evidently due to the fact that in 
this country the greatest number of searchers have been at work on this 
group. . 
