390 THE ZOOLOGIST. 



noticed that the small stream referred to was full of young pike. 

 They have evidently not that confidence in the element displayed 

 by the edible frog, for, though they jump momentarily into the 

 water on being pursued, they immediately proceed to climb up 

 the bank again, and seek refuge on dry land. This behaviour is 

 singularly analogous to that of the marine Amblyrhynchus* and 

 seems, like it, to be induced by a " fixed and hereditary instinct" 

 of which we may recognise the probable origin in the imperfectly 

 developed web of the posterior feet. 



4. Rana agilis, Thomas. — This is another of the species whose 

 existence in Baden has not yet been verified. I recollect, about 

 1884, finding a frog in the "Wildpark" of Karlsruhe, which 

 struck me by its prodigious leaps and the peculiar long-drawn 

 cry which it emitted on being captured ; but otherwise I took no 

 further notice of it. Without attaching any importance to this, 

 I cannot help thinking that, in a country so favourably situated 

 as Baden, the presence of this batrachian has as yet merely been 

 overlooked through the paucity or absence of sufficiently eager 

 observers. 



It was first signalled as a German species by Dr. Boettger 

 from the neighbourhood of Strasburg,t later on by Leydigt from 

 near Wiirzburg, two points between which a great part of the 

 Grand Duchy lies. It has already been recorded from Switzer- 

 land (Fatio, 1861), Hungary (Mehely, 1890), Bohemia (Wolters- 

 torff, 1890), besides a large part of France, so that it will 

 presumably turn up in more localities of the intervening part of 

 Germany. 



rarer cases, an incomplete physiological substitute for the lost member. 

 Owing to the position of the eyes, frogs have some difficulty in seeing what 

 is directly before them, and may sometimes be seen, when swimming 

 rapidly, to strike with the snout against the leaves or stalks of aquatic plants. 

 But for many injuries to batrachians it appears we must hold the mollusca 

 responsible. One observer relates how a R. esculertta, in its precipitate 

 haste, was received head foremost into the opened valves of a mussel, to the 

 surprise, doubtless, of both parties. I observed a case of multiple digits with 

 a Triton ma/rmoratu8, from near Paris, which possessed no less than eight 

 toes on one front foot (otherwise normal). This may have been congenital. 



■•'• Darwin, 'Voyage of a Naturalist,' p. 387. 



f ' Zoologischer Anzeiger,' 1880. 



I ' Triton liclvcticus und li. agilis,' 1888 ; and ' Uber unsere braunen 

 Prosohe,' 1889. 



