. Journal of morphology. arthenogenesis. The transmission of hereditary charactersthrough the sperm is in many cases merely an accessory becomes of vital importance only in those forms where the maleis heterozygous for sex and where the species can only be propa-gated through sexual reproduction. If the sperm nucleus be chemically almost identical with theegg nucleus it is- possible for it to force one or a few charactersupon the developing embryo. If the difference between sperm andegg nucleus exceed a certain limit—which structural chemistrymay one day be able to define—the hered
. Journal of morphology. arthenogenesis. The transmission of hereditary charactersthrough the sperm is in many cases merely an accessory becomes of vital importance only in those forms where the maleis heterozygous for sex and where the species can only be propa-gated through sexual reproduction. If the sperm nucleus be chemically almost identical with theegg nucleus it is- possible for it to force one or a few charactersupon the developing embryo. If the difference between sperm andegg nucleus exceed a certain limit—which structural chemistrymay one day be able to define—the hereditary influence of thespermatozoon is as a rule completely or almost completely oblit-erated; and the result is a purely maternal larva, rendered moreor less sickly through the presence or formation of foreign orfaulty substances. The camera drawings of the sea-urchin larvae were made byMr. W. 0. R. King, those of the fish embryos by Mr. Bagg. Toboth gentlemen I wish to express my thanks. 10 JACQUES LOEB BeatingHeart. Fig. 14 Hybrid between Fundulus heteroclitus 9 and Menidia c?, three weeks old. HEREDITY IN HETEROGENEOUS HYBRIDS 11 Beating ^.Heart^•^journalofmorphol23wist
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Keywords: ., bookcentury1900, bookdecade1, booksubjectphysiology, bookyear1912
