. The Intellectual observer. Fie. 8. tail, with fringe ii. Before this cercaria becomes sexuallymature it passes through the stage represented in Fig. 8, having Natural History of Entozoa. 195 previously encysted itself. The drawing represents the escapefrom the cyst.* Fig. 9 represents the young Distoma militarein a sexually immature state. With the help of previousdescriptions the several parts will be easily recognized. Greatercomplications than those we have mentioned occur in thereproduction and development of these worms; but for fulldetails we must refer to Dr. Cobbolds Fig. 9. A
. The Intellectual observer. Fie. 8. tail, with fringe ii. Before this cercaria becomes sexuallymature it passes through the stage represented in Fig. 8, having Natural History of Entozoa. 195 previously encysted itself. The drawing represents the escapefrom the cyst.* Fig. 9 represents the young Distoma militarein a sexually immature state. With the help of previousdescriptions the several parts will be easily recognized. Greatercomplications than those we have mentioned occur in thereproduction and development of these worms; but for fulldetails we must refer to Dr. Cobbolds Fig. 9. According to Pagenstecher—as cited by Cobbold—the eggsof the Trematoda, to which the flukes belong, vary in size, form,and colour. When mature they contain a ciliated or non-ciliated embryo. These eggs are, by various means, conveyedto the bodies of mollusks, and the germs they contain aredeveloped into what are called nurses, some of which aremore highly organized than others. These nurses produceoffspring of the bud sort. Tailed trematode larvse (cercarix), * a Month, i cephalic sucker, c pharyngeal bulb, d oesophagus, e e digestivecceca, f coronal spines, g contractile vesicle, h water vascular vessels, i i yelk-forming glands, Tc I cellules from which other reproductive organs will grow. VOL. VI.—NO. Ill, 0 196 Natural History of Entozoa. as well as redice (or nurses), are developed within the redias,this variation of nurse-contents probably depending on When the immature contents of both nurse-forms(i. e., of sporocysts and rediee) are accidentally set f
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