828 REPORT— 1897. 



4. 071 Internal Absorption of Hemoglobin and Ferratin. 

 By F. W. G. Mackay. 



5. On Secretion in Gland Cells. By R. R. Bensley. 



'C. TJie 2forphology and Physiology of Gastric Cells. By R. R Bensley. 



.7. Visual Reaction to Intermittent Stimulation. By O. F. F. Grunbaum. 



The factors upon wliich fusion of intermittent retinal stimuli depends have 

 apparently been noted singly, and never collectively considered. 



Scbafhautl found that, on increasing the strength of the stimuli, increase in 

 frequency was necessary to produce fusion : speed of translation was observed by 

 Filehne to have an effect. 



Charpentier and Baader pointed out that the size of the field of vision was an 

 important factor, and Sherrington has recently demonstrated the effects produced 

 by simultaneous contrast. 



Experiments have been made, bearing in mind the above facts, along with the 

 necessity of guarding against fatigue. 



It was found that if the field of vision were small, so that the image fell 

 entirely within the fovea, and the speed of translation great, it was impossible to 

 discern that the stimulus was intermittent above sixty-three alternations per 

 second. 



It must be noted that when the source of light is within focal range, and of a 

 nature that can be focussed, there is no sudden transition from the recognised 

 •coarse flicker to that of a smooth, steady sensation, but an intermediate stage of 

 fine flicker or tremor of the field is experienced. 



If the stimulus be greatly increased, the maximum frequency at which discon- 

 tinuity of stimulation is observed may fall to forty-five alternations per second 

 before pathological phenomena ensue. 



If the speed of translation be small, discontinuity of stimulation may be 

 •observed at 600 alternations per second, with practice, but then only through a 

 short range of luminosity. On increasing the strength of stimuli, the frequency 

 must be rapidly diminished in order to discern discontinuity. 



The effect of speed of translation is well shown by keeping the luminosity 

 constant, and using rotating discs with varying numbers of sectors : it is then 

 found that one with many sectors, and consequently a slow speed of translation, 

 will require a high frequency of alternation to produce fusion, while one with but 

 few sectors will fuse with a frequency of alternation of sixty-three per s3cond or 

 below. This is probably due to unconscious simultaneous contrast. 



• 8. Functional Development of the Cerebral Cortex in Different Groiips of 

 Animals. By Wesley Mills, M.A., <&c., Professor of Physiology in 

 McGill University, Montreal. 



The purpose of the research described in this Paper is to determine whether 

 the cerebral cortex is functional at birth, and, if not, then how soon afterwards in 

 several species of animals, those being selected that are most commonly emploj^ed 

 for physiological experiments and are best known. 



The method of investigation was described, illustrated protocols of experiments 

 rgiven, and inferences drawn for each species of animal the subject of experiment. 



The paper concluded with a criticism of the work of other investigators, and 

 with some general deductions. 



