. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SEXUAL PHASES IN TERRESTRIAL NEMERTEANS 417 nett is likewise hermaphroditic and, as pointed out by Hett (1928), re- sembles G. palacnsis so closely as to suggest specific identity. All the above are known or assumed to be oviparous but the land nemertean of Bermuda, G. agricola (Will. Suhm), has been shown to be irregularly protandric, hermaphroditic and viviparous (Coe, 1904). The egg clusters of G. austral iensis have been described by Dendy (1893) and those of G. dcndyl by Waterston. and Quick (1937). Also one of the spec
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SEXUAL PHASES IN TERRESTRIAL NEMERTEANS 417 nett is likewise hermaphroditic and, as pointed out by Hett (1928), re- sembles G. palacnsis so closely as to suggest specific identity. All the above are known or assumed to be oviparous but the land nemertean of Bermuda, G. agricola (Will. Suhm), has been shown to be irregularly protandric, hermaphroditic and viviparous (Coe, 1904). The egg clusters of G. austral iensis have been described by Dendy (1893) and those of G. dcndyl by Waterston. and Quick (1937). Also one of the specimens of G. palacnsis studied by Hett (1928) had an egg cluster attached to the proboscis. jncl spy und spy'. FIG. 1. Geonemertcs agricola. Portion of horizontal section of body dorsal to nerve cords, showing sections of two'embryos (e, e') nearly ready for birth. Small gonads representing young ovaries (ovy), young spermaries (spy), sperma- ries with ripe spermatozoa (spy'), gonads of the hermaphroditic type (k), as well as others still remaining undifferentiated (und) are already present in anticipation of the following sexual phases. Other letters represent: br, brain of embryo; cp, epithelium of body wall; id, intestinal diverticula; I in, longitudinal musculature of body wall; p, proboscis of embryo, par, parenchyma. Slightly diagrammatic. SEXUAL PHASES IN G. AGRICOLA The study of more than a hundred individuals representing all ages of G. agricola shows that the young worms are usually protandric, since at first sexual maturity they have their bodies distended with spermaries. After the discharge of the sperm or sometimes earlier, ovaries begin to develop and the ovocytes slowly grow to maturity in the first female. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marine Biological Laboratory (Woods Hol
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
