The writer has previously reported that extracts of the ovaries of a Bermuda echinoderm (Lytechinus variegatus) caused considerable growth of the epithelium of the uterus and vagina when injected into the mature, ovariectomized rat.
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However, failure of the uterus to swell with fluid as it does in full normal estrus indicated that the response was subthreshold and, possibly, that the stimulating agent in the extracts differed in some respects from estrogens derived from mammalian sources. The present study was undertaken in order to test for estrogens in other invertebrate ovaries and to make further observations of the effects of the ovarian extracts upon the vaginal and uterine epithelium of the rat.
The ovaries of the common sea urchin (Lytechinus variegatus), the reef urchin (Echinometria), the holothurian (Stichopus mobii), and the lobster (Palinurus argus) were collected in Bermuda during the summer of 1938 in considerable quantities. In all cases the ovaries were sexually mature or were rapidly approaching that state when collected. After removal the ovaries were drained of as much sea water as possible and then thoroughly ground in a mortar. The ground tissues were then placed in separate containers of 95%
