PROCEEDINGS OF THE SOCIETY. 
183 
It was shown that this correction for foreshortening was essential in 
cases where a system of squares is to be projected upon the microscopic 
specimen ; and further, that it can be made in a very simple manner by 
suspending the ruled glass plate in such a manner as to allow its upper 
margin to tilt forward until an equal number of vertical and horizontal 
squares appear in the field of the Microscope. 
These points were illustrated by setting up a Microscope in such a 
manner as to show the image of a system of squares superposed upon a 
film of blood. 
Prof. Wright also called attention to a Microscope made by Messrs. 
Swift, in which a very simple plan had been adopted of swinging the 
substage condenser in and out of the optical axis. 
Dr. J. L. Williams read a paper ‘ On the Formation and Structure of 
Dental Enamel,’ the subject being illustrated by a large number of 
photomicrographs of mounted sections shown upon the screen, some of 
these showing an amplification of x 3000. 
Mr. J. Howard Mummery said he felt sure that all the Members 
present who did any work in photomicrography would appreciate the 
great beauty of the slides shown by Dr. Williams, especially when they 
recognised the extreme difficulty of photographing the microscopic 
structure of enamel. It had always been a matter of some difficulty to 
understand how the growing enamel was nourished during the earlier part 
of its development, the blood-vessels being then separated from the 
stratum intermedium and ameloblasts by the stellate reticulum ; but if, as 
Dr. Williams suggested, the meshes of the stellate reticulum are occupied 
at this time by large cells, the matter was explained. In the photograph 
shown it was rather curious to notice that all the nuclei of these cells 
seemed to be at the intersections and not in the middle of the cell ; but 
this might be only an accidental result of the preparation of the speci- 
men. In the later stages of enamel development the slides showed very 
distinctly the presence of an abundant blood supply in the stratum 
intermedium, and he certainly considered that Dr. Williams’ communi- 
cation demonstrated these points in the development of enamel very 
clearly, and he looked upon it as the most valuable contribution to the 
study of the development and structure of enamel that had been made 
for many years. 
The President said he could most heartily concur in the opinion 
expressed by Mr. Mummery as to the great excellence of the slides 
which had been exhibited, and all would agree with him as to the very 
lucid way in which the subject had been presented. He had great 
pleasure, therefore, in moving a very hearty vote of thanks to Dr. 
Williams for his communication, and for one of the most beautiful 
lantern exhibitions that they had seen for some time. 
The vote of thanks was put to the meeting, and carried by acclama- 
tion. 
