. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. STIMULATION OF SPAWNING IN MALE OYSTER 131 volving the contraction of the larger group of muscle fibres. In the ex- periments with egg water the reaction of tentacles was so indistinct that no determination of the latent periods could be made. The contraction of the mantle was, however, quite noticeable and the effect was observ- able even in dilutions of 1 per cent of standard egg water. The results of one experiment presented in Table X show that the mantle reacted to the concentrations of stimulant which were not strong e
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. STIMULATION OF SPAWNING IN MALE OYSTER 131 volving the contraction of the larger group of muscle fibres. In the ex- periments with egg water the reaction of tentacles was so indistinct that no determination of the latent periods could be made. The contraction of the mantle was, however, quite noticeable and the effect was observ- able even in dilutions of 1 per cent of standard egg water. The results of one experiment presented in Table X show that the mantle reacted to the concentrations of stimulant which were not strong enough to induce ejaculation. It should be noted that in using 30 per cent egg water, ejaculation occurred only with the fourth dose. In all the experiments conducted with various concentrations of egg water the contractions of the mantle preceded ejaculation. The latent period of ejaculation was somewhat lower than in the intact males. TABLE XI Sensory stimulation and ejaculation provoked by per cent thyroidin solution. Temperature, 22-23° C. Observations of mantle reaction omitted. Latent Period in Second. i Time Tentacle Muscle Ejaculation _ + * , _____ * Positive reaction, latent period not determined. — No reaction. Tentacles were found to be very sensitive to per cent of thyroidin, repeated application of which resulted in a complete narcosis of these organs. Paralysis of tentacles did not interfere with ejaculation (Table XI) which proceeded in a normal way. There is no evidence at pres- ent that the receptors of sexual stimuli are located in the tentacles and the observation that ejaculation may be provoked when the latter are paralyzed speaks against this assumption. The location of the receptors still remains to be found. Experiments with egg water suggest that they may be present in the mantle. Biological Significance of Spawning Reactions of
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
