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Bryophytes, http://name.umdl.umich.edu/IC-HERB00IC-X-706218%5DMICH-B-706218_E, https://quod.lib.umich.edu/cgi/i/image/api/thumb/herb00ic/706218/MICH-B-706218_E/!250,250, The University of Michigan Library provides access to these materials for educational and research purposes. Some materials may be protected by copyright. If you decide to use any of these materials, you are responsible for making your own legal assessment and securing any necessary permission. If you have questions about the collection, please contact the Herbarium professional staff: herb-dlps-help@umich.edu. If you have concerns about the inclusion of an item in this collection, please contact Library Information Technology: libraryit-info@umich.edu., https://www.lib.umich.edu/about-us/policies/copyright-policy

Pteridophytes, http://name.umdl.umich.edu/IC-HERB00IC-X-1606041%5DMICH-V-1606041_E, https://quod.lib.umich.edu/cgi/i/image/api/thumb/herb00ic/1606041/MICH-V-1606041_E/!250,250, The University of Michigan Library provides access to these materials for educational and research purposes. Some materials may be protected by copyright. If you decide to use any of these materials, you are responsible for making your own legal assessment and securing any necessary permission. If you have questions about the collection, please contact the Herbarium professional staff: herb-dlps-help@umich.edu. If you have concerns about the inclusion of an item in this collection, please contact Library Information Technology: libraryit-info@umich.edu., https://www.lib.umich.edu/about-us/policies/copyright-policy

Pteridophytes, http://name.umdl.umich.edu/IC-HERB00IC-X-1606041%5DMICH-V-1606041_E, https://quod.lib.umich.edu/cgi/i/image/api/thumb/herb00ic/1606041/MICH-V-1606041_E/!250,250, The University of Michigan Library provides access to these materials for educational and research purposes. Some materials may be protected by copyright. If you decide to use any of these materials, you are responsible for making your own legal assessment and securing any necessary permission. If you have questions about the collection, please contact the Herbarium professional staff: herb-dlps-help@umich.edu. If you have concerns about the inclusion of an item in this collection, please contact Library Information Technology: libraryit-info@umich.edu., https://www.lib.umich.edu/about-us/policies/copyright-policy

The female of D. fujiama Fraser has a 2n = 24 karyotype, including a pair of X chromosomes which are similar in size and the largest elements in the complement. The males of both D. fujiama and D. m. moiwanus (Okumura) have the same number of chromosomes, 2n = 23 and n = 12; in each sp. a single X chromosome, which is the largest element, is always observed in the spermatogonial karyotype. At diakinesis and early Ml, the X chromosome consisting of a pair of chromatids is easily distinguished from the autosomal bivalents on account of their different morphology. Preliminary examination of C-banded spermatogonial metaphases and spermatocyte complements at diakinesis in D. fujiama indicates that discrimination between the X chromosome and the autosomes is easy because of a peculiar distribution pattern of constitutive heterochromatin of the X chromosome. Such chromosomal evidence reveals that D. fujiama is characterized by a male heterogametic sex chromosome system of the XO/XX-type. No m-chromosome could be encountered in either sp.

Arguments are presented for the 3 generally recognized taxa of the genus Mnais Selys occurring in the Japanese Islands to be regarded as independent spp., viz. M. costalis Selys, M. pruinosa Selys, and M. nawai Yamamoto. It is pointed out that the M. pruinosa populations occurring in central Honshu (the Setouchi Group) are also possibly an independent sp. to be distinguished from those occurring in southwestern Japan (the Nankai and Saikai Groups). Essentially the same combination of forms (a heterochromatic orange-winged, occasionally pale-orangeor dark-brown-winged male, a homoeochromatic hyaline-winged male, and a homoeochromatic hyaline-winged female) seems to occur in most districts of the Japanese Islands. Based on the taxonomic arrangement of the known forms, the evolution of the Japanese Mnais spp. is discussed. The present geographic distribution of the taxa and the combination of forms in various districts are interpreted by a working hypothesis based on the so-called "competitive exclusion (or displacement) principle" and a consequent "character displacement”.