JOHN MASTIN, M.A. D.Sc. Ph.D. Litt.D.

F.S A.SCOT. F.L.S. F.C.S. F.R.A.S. F.R.M.S. R.B.A.

Author of "Parasites of Insects," "The True Analysis of Milk," "Plate-Culture and Staining of Amœbæ," etc., etc.

London

E. & F. N. SPON, Limited, 57 HAYMARKET

NEW YORK

SPON & CHAMBERLAIN, 123 LIBERTY STREET

1911