Male Gamete Development Research Articles

Studies of Spermatogenesis in the Hepaticae. IV. On the Blepharoplast of Blasia

Spermatogenesis in Blasia pusilla L. was reexamined with electron optics to help evaluate conflicting results of the two earlier light microscope studies of this species. The present micrographic resumé of spermatid transformation confirms Sharp's observation of centrosomes in very young spermatids and agrees with Woodburn's general account of spermatozoid maturation. Further, male gamete development in Blasia is shown to be closely comparable to that of Marchantia and Pellia. It is concluded that Sharp's report of blepharoplast development in Blasia by fragmentation and coalescence was based on anomalous plant material.

OBSERVATIONS ON THE GENITAL SEGMENTS OF SPIRORBIS (POLYCHAETA)

1. In all species of Spirorbis examined, the first two or three abdominal segments of mature adults are female and the remaining abdominal segments are male. Both female and male gametes differentiate simultaneously in the same individual and arise from a discrete and persistent gonad composed of primordial germ cells arranged in two retroperitoneal rows, mesial to the ventral nerve cords, and running the length of the abdominal segments.2. Cytological events associated with the development of female and male gametes are described. Differentiation of oocytes and spermatocytes occurs freely within the coelomic cavity without the aid of attached nurse cells.3. Although coelomostome rudiments are present in both female and male segments, functional genital ducts do not develop. Spawning is assumed to take place by rupture of the body wall.

Preliminary Note on Ceratozamia

Previous articleNext article FreeBriefer ArticlesPreliminary Note on CeratozamiaCharles J. ChamberlainCharles J. Chamberlain Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 43, Number 2Feb., 1907 Article DOIhttps://doi.org/10.1086/329111 Views: 14Total views on this site Citations: 5Citations are reported from Crossref Journal History This article was published in the Botanical Gazette (1876-1991), which is continued by International Journal of Plant Sciences (1992-present). PDF download Crossref reports the following articles citing this article:Zlatko Kvaček A new Tertiary Ceratozamia (Zamiaceae, Cycadopsida) from the European Oligocene, Flora - Morphology, Distribution, Functional Ecology of Plants 197, no.44 (Jan 2002): 303–316.https://doi.org/10.1078/0367-2530-00044Alok Moitra, S. P. Bhatnagar Ultrastructure, cytochemical, and histochemical studies on pollen and male gamete development in gymnosperms, Gamete Research 5, no.11 (Jan 1982): 71–112.https://doi.org/10.1002/mrd.1120050108CLARENCE STERLING STRUCTURE OF THE MALE GAMETOPHYTE IN GYMNOSPERMS, Biological Reviews 38, no.22 (May 1963): 167–203.https://doi.org/10.1111/j.1469-185X.1963.tb00782.xA. Anstruther Lawson VI.—A Contribution to the Life-History of Bowenia, Transactions of the Royal Society of Edinburgh 54, no.22 (Jul 2012): 357–394.https://doi.org/10.1017/S0080456800027630 H. A. Jones Physiological Study of Maple Seeds, Botanical Gazette 69, no.22 (Sep 2015): 127–152.https://doi.org/10.1086/332622