404 
Notes on Portrait-plates 
statue of Johannes Muller stands before the Stadthaus at Coblenz. The 
well-known portrait of Muller which we reproduce was taken in 1857, a year 
before his death. The face shows extraordinary energy. 
Joseph Leidy 
1823-1891. 
(Portrait-plate VII, follows VI.) 
Leidy was born 9 September, 1823, and died 30 April, 1891, at Philadelphia. 
He was of French-German extraction, his forefather Carl Leidy having 
migrated to Pennsylvania about 1704. At an early age Leidy showed an 
aptitude for drawing, a talent that he made use of in connection with his 
scientific work. After taking his M.D. at the University of Pennsylvania in 
1844, he practised medicine for two years. He then took up natural history 
and became Prosector and Curator of the Academy of Sciences of Philadelphia 
(1846) at the age of 23. When he was 30 he became Professor of Anatomy, 
subsequently he was Professor of Zoology and Comparative Anatomy. 
Of Leidy’s 550 papers, no less than 120 relate to helminths. His contribu¬ 
tions cover a wide field however, for they relate to mineralogy, botany, 
vertebrate and invertebrate comparative anatomy, and palaeontology. His 
papers on Protozoa and Helminths were important. He discovered Trichina 
spiralis in the pig (1846), and this led Leuckart to make the important sug¬ 
gestion that man might become infected by eating raw pork. In 1850-1856 he 
wrote on various helminths and his Synopsis of Entozoa appeared in 1856. In 
1871 he commented on flies as agents in the carriage of contagious disease, 
and from this time onwards he seems to have worked mainly on parasites and 
Rhizopods. He wrote on miscellaneous parasites, Gregarines, Cestodes, Tre- 
matodes, Nematodes, Hirudinea, parasitic Crustacea, Acari and Insecta. All 
who knew him remember him as possessed of a most attractive personality. 
For biography see H. B. Ward (1900), Arch, de Parasitologie , hi. 269-279, 
with portrait as an older man, facsimile signature and letter and a short list 
of his parasitological papers. A fuller bibliography will be found in Stiles and 
Hassall’s Index (1906, pp. 1050-1057) and in Leidy’s Researches in Helmintho¬ 
logy and Parasitology , published by Joseph Leidy jr. in 1904. Leidy left much 
work on helminths and gregarines unpublished. I am indebted to his sons 
for the excellent portrait herein reproduced. 
*>e- 
Edward Jenner 
1749-1823. 
(Portrait-plate VIII, facing p. 404.) 
The discoverer of vaccination, Edward Jenner was born on 17 May, 1749, 
and died on 26 January, 1823, at Berkeley, Gloucestershire, where he lies buried 
in the Parish Church. The son of a clergyman, he took an interest in natural 
