The order Lepidoptera has long furnished a favorite material for cytology, and the extensive study of chromosomes has been made from the cyto-taxonomic standpoint. With reference to the chromosome list published by Makino (1951), it is clear that chromosome research of the Heterocera, a group of the moth, has much advanced on a largescale including about 170 species, while in the Rhopalocera, a group of the butterfly, the investigation has comparatively less extended than in the Heterocera, the chromosomes of some 150 species having been reported so for. The comparative studies of the European

The taxonomy, variation and distribution of butterflies have been dealt with by a number of lepidopterists on the basis merely of morphological characters. Recently, chromosome cytology has contributed significantly to insect systematics by emphasizing the cytotaxonomic differences which exist between related species. Cytologists are concerned with differences between species in chromosome number or in the sizes and shapes of some of the chromosomes, since such differences may sometimes be

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