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Show 1894.] TADPOLE OP XENOPUS LiEVIS. 103 the latter animal this constriction is due to a bulging of the body in the region of the pronephros. This bulging is less marked in the tadpoles of Xenopus. The dorsal fin commences just before the median occipital elevation begins to slope away posteriorly; the ventral fin commences just in front of the accurately median anus. The " abdomen " has a metallic glitter, and becomes much more swollen and relatively shorter in the later stages. The fins are continuous to the very end of the tail; there is no " Chimaeroid lash " as depicted by Parker 1. Habits.-The tadpoles generally rested in the water with the head downwards and the tail in constant wriggling motion. Whether this is connected with respiration or not I a m unable to say. In any case I detected no special vascular supply or mechanism of any kind which might be related to such a function. The food of the tadpoles consisted entirely of Cyprids, with which the tank, where they were housed, swarmed. Their intestines were invariably full of these Crustaceans and of nothing else. In spite of their purely carnivorous diet, the intestine was just as much coiled as in the common tadpole. The carnivorous diet, it should be remarked, was adopted from choice and not from necessity. There was plenty of water-weed upon which they could have fed. It is generally stated that the tadpole of the Common Frog is a vegetarian. It will, however, eat animal food, such as the dead bodies of its companions ; it can also be compelled to take to a purely carnivorous regimen. The following is a brief statement of the measurements and general characters of tadpoles at various stages. Stage I. Four specimens of the first stage were preserved in Perenyi fluid at 10 A.M. on M a y 29, i. e. 12 to 15 hours after hatching. The total length of the tadpoles is after preservation 5 millim. Corresponding to tadpoles of same lengths figured by Marshall and Bles. Stage II. Preserved at 12 midday on M a y 30. Three individuals as nearly as possible of the same length, i. e. 7 millim. Corresponding more or less to 9 millim. in tadpole figured by Marshall and Bles! the relative proportions of body to tail are 2 : 3. Stage III. Preserved on June 1st. Length 8 millim. The form of the 1 ^lult tadpole fully established. Length of body to that of tail as o : o . 1 The appearance occurs, however, in spirit-specimens, owing to the clingine of the membranous fins to the solid part of the tail clinging a n u s ^ m e a S u r e m e n t of the hod7 is « « * to end 'of swollen abdomen, not to |