Abstract
Nine attempts to infect kittens directly with E. histolytica macacorurn by means of amoebae (per anum) or cysts (per os) in the faeces of 2 M. sinicus (Polo and Susanna) and 1 M. rhesus (Jacko), were wholly unsuccessful. Four similar experiments with cysts (per os) from another M. sinicus (Bonar) gave 2 positive (Kittens 28 and 31) and 2 negative results.Attempts to transmit strains of E. histolytica macacorum from one species of Macacus to another have been uniformly successful.A strain (D.) of E. histolytica, derived from a man suffering from acute amoebic dysentery, has been cultivated in vitro continuously for 5½ years.(i) The fact has been confirmed that strains of E. histolytica which, when newly isolated, are infective for kittens, may lose this infectivity after continued cultivation in vitro.