BOOK NOTICES 4SI

to the subjects dealt with in the litera­ture. The whole is well printed in good type, setting an example that will be appreciated by those who have to deal with blindness. The unique value of this book appears, when we know that the author became blind at the age of eleven years ; and continued his studies to a Master's Degree, from the Univer­sity of Oregon. Edward Jackson.

G l a u k o m und Netzhautzirkulation (Glaucoma and retinal circulation). By Maximilian Salzmann. Paper covers, 68 pages, 41 illustrations in the text. Price 8 marks. 1933, Ver­lag von S. Karger, Berlin.

This monograph is reprinted from part fifteen of Abhandlungen aus der Augenheilkunde und ihren Grenzgebie­ten. It presents in some detail the pathologic findings in a series of eyes which had been enucleated after symp­toms of absolute glaucoma ; and the con­dition of these eyes is viewed especially as regards the relation between glau­coma and the circulation in the central retinal vein. There has been a good deal of discussion as to the reciprocal rela­tionship between glaucoma and venous obstruction as cause and effect. The production of glaucoma by venous ob­struction has long been recognized, but venous obstruction secondary to glau­coma has been regarded as exceptional. Salzmann is disposed to regard the two conditions as constituting a sort of vi­cious circle. Some importance is at­tached to an intercalary tissue (Schalt­gewebe) described by Elschnig in 1899, and found by Salzmann in about one-third of his eighty cases. This tissue, which arises at the optic disc and pene­trates into the supportive structure of the nerve head, probably has an impor­tant influence in producing compression of the central vein. W. H. Crisp.

Corresponding Retinal Points, The Horopter and Size and Shape of Ocular Images. By A. Ames, Jr., Kenneth N. Ogle and Gordon H. Glidden. Paper, Octavo, 96 pages, 61 illustrations. Hanover, New Hampshire, 1932.

This is a report of work done in the Department of Research in Physiologi­cal Optics, Dartmouth Medical School, and is a reprint from the Journal of the Optical Society of America, vol. 22, pp. 538-631. It describes exact observa­tions, made with newly devised labora­tory instruments, carried on with great exactness and attention to details, and interpreted from the points of view of the physicist, pathologist and mathema­tician.

The summary of this work holds: That "the concept that associates spe­cific subjective directional values (lines of direction, Helmholtz) with specific cortical centers is fundamental. The op­tical projections of the retinal points represent the effective distribution of the spatial values, associated with the specific cortical centers to which the retinal points are connected."

The general conclusions are given thus:

"(1) The studies indicate that the re­lationship between subjective and ob­jective space and directional values are subject to more exact measurement, than had heretofore been recognized.

"(2) They indicate that a mathe­matical comprehension and formulation of the empirical longitudinal horopter data are possible ; first, through an im­proved method of obtaining, handling, and analyzing the empirical data; sec­ond, through the elimination of those factors that can be neglected; and, third, through empirically checking the magnitude of changes introduced by known factors.

"(3) It would appear that the funda­mental hypothesis of specific directional values associated with specific brain centers is placed on a firmer basis.

"(4) It would appear that certain complex phenomena associated with binocular vision, heretofore calling for psychological interpretation, have been given a physiological explanation."

If the methods of exact mathematical analysis and broad deductions here used, should be applied to the groups and associated impressions, received from the rods near the periphery of the retina, it is probable that our knowledge of the peripheral fields of vision and of