Mesozoa, [128].

Metazoa, [27], [28], [111], [145];

old age of, [157].

Metschnikoff, on pole-cells, [197].

Micellae, [190], [194].

Mimetic forms, [264], [280].

Mimosa, ‘after effects’ in, [404].

Minot, on cyclical development, [199];

on polar bodies, [214], [225], [340], [345], [353].

Moina, winter eggs of, [118], [240];