MacCallum belonged to that type of scientists whom we may designate as discoverers. His results were obtained quickly, were made secure beyond doubt, and were put into such shape that they could easily be demonstrated by him. But as is also common in the case of discoverers, his publications were comparatively brief. This may make it at times difficult for inexperienced or uncritical workers to repeat his experiments. I may state, however, that they belong to the regular class exercises of the medical students in our laboratory. Those who have once learned how to perform them can always count upon their succeeding.
In his work as well as in his life he was a calm thinker, the reverse of a hustler. He conceived his experiments in the spirit of an artist and the realization of his ideas was the poetry his work put into his life. He did not work for outside success, nor did he pose as a benefactor of mankind.
Those who have known him well feel that the death of John Bruce MacCallum has left a gap which will never again be filled.
Jacques Loeb.
Berkeley, November 7, 1906.
FOOTNOTES:
[1] Quoted from a letter from his brother, Professor W. G. MacCallum, of Johns Hopkins University, to whom I am under obligation for the data given in this sketch.
PUBLICATIONS BY JOHN BRUCE MacCALLUM.
1. Fresh-water Cladocera.
University of Toronto Quarterly, May, 1895.
2. On the Histology and Histogenesis of the Heart Muscle Cell.