Plasmodium tenue Laveran and Marullaz, 1914

SYNOPSIS.Plasmodium tenue was described briefly by Laveran and Marullaz in 1914, and seems to have been studied by no one since. Indeed only Wenyon reports having seen it. The discoverers saw it in the blood of Liothrix luteus (a babbler, but often mistakenly called a Pekin robin or Chinese nightingale). Partly because of the small size of the parasite and partly because it had been found in a “robin,” it has since been generally thought to be a synonym for Plasmodium vaughani , so common in America robins. Plasmodium tenue usually produces 4 merozoites per segmenter, but often as many as 6; rarely it apparently gives rise to only 2 or 3. Gametocytes are elongate, and neither sexual nor asexual stages displace the host cell nucleus. Altho very similar to Plasmodium rouxi in structure, and also to certain other recently found members of the group, it seems to be a valid species of the subgenus Novyella. Canaries seem insusceptible, at least to blood‐induced infection, and its structure and behavior have therefore been studied in the original host, of which a number of individuals have been found infected. By contrast, canaries are readily susceptible to Plasmodium rouxi , and also to P. vaughani. In vaughani malaria, whether in the robin or canary, larger asexual stages usually have a conspicuous refractile granule.