Müller, H., on colours of flowers, [259];
on nectaries, [307].
Multicellular organisms, division of labour in, [27].
Musca domestica, length of life of, [43].
Musca vomitoria, polar bodies of, [353].
Myopia, [89].
on idioplasm, [174], [182], [190], [201], [340], [414];
on inherent tendency to vary, [256], [298];
on Alpine plants, [269];