PELOBATIDAE 163 



my interference, with the specimens which share their abode with 

 several species of Aviblystoma and Spelerpes ; there are heard 

 now and then sudden loud yells, like the squeak of a cat or the 

 yapping of a little dog. 



In the spring the Spade-footed Toads take to the water for 

 about a week, and the male's call-note is an ever-repeated cluck- 

 ing sound, which can also be produced under water, with the 

 mouth shut, the air being shifted backwards and forwards through 

 the larynx. The male grasps his mate below the waist ; the eggs 

 are combined into one thick string, which is about 18 inches 

 long, and is wound round and between the leaves and stalks of 

 water-plants. The eggs measure 2-2'5 mm., and are very 

 numerous, a large string containing several thousands. The 

 larvae are hatched on the fifth or sixth day in a very unripe con- 

 dition. They are only 4 mm. long, quite black, and still devoid 

 of giUs and tail. They attach themselves to the empty gelatinous 

 egg-membranes, which they possibly live upon. On the following 

 day the tail begins to grow ; two days later fringed external gills 

 sprout out and serve for about ten days, when they in turn give 

 way to new, inner gills. The little tadpoles then leave their moor- 

 ings and become independent. The hind-limbs appear in the 

 ninth week, the fore-limbs in the twelfth. At the age of three 

 months they begin to leave the water. The most remarkable 

 feature is the enormous size of the full-grown tadpole, the body of 

 which is as large as a pigeon's egg ; the usual total length, 

 including the tail, amounts to about 4 inches or 100 mm., but 

 occasionally regular monsters are found. This was the case some 

 thirty years ago, when the Berlin Museum received a number of 

 tadpoles, the largest of which measured nearly 7 inches. They 

 were found in the month of December near Berlin, in a deep clay- 

 pit with high, steep walls, so that the tadpoles were prevented 

 from leaving the water. Similarly hemmed-in broods probably 

 hibernate in the water under the ice, and such instances have 

 been recorded. Normally they metamorphose into the much 

 smaller toad within the same year. 



P. cultripes. — This is the Spade-foot of the whole of Spain and 

 Portugal and of the southern and western parts of France. It 

 is similar in habits to P. fuscus, from which it differs but 

 slightly. The tarsal spur is black, and there is a parieto- 

 squamosal bridge which completely roofs over the temporal fossa 



