ECOLOGY OF TADPOLES 



51 



Chlnmydomofias could be seen "passing back in a kind of helicoidal 

 vortex towards the oesophagus, where the two green currents converge 

 and disappear." Kratochwill (1933) has a drawhig of a section of these 

 parts of R. a^ilis showing food particles in this place. Dodd (1950) 

 was probably the first to publish the fact that mucous cords form there 



MUCOUS 

 CORD 



DORSAL VELUM 



NASAL 

 AVITY 



GILL 

 FILTER 



TONGUE 



VENTRAL VELUM 



Fig. 17. Sagittal Section of a Tadpole of R. temporaria. Showing 

 the Structures of Importance in Feeding 



MUCOUS CORD 



DORSAL VELUM 



FOOD 



PARTICLES 



VENTRA 



:lum 



GILL CLEFTS 



Fig. 18. Diagrammatic View of the Mouth and Pharynx of a 



Tadpole, Showing the Path Taken by the Water and die Structures 



of Importance in Feeding 



in R. temporaria and in B. hufo. I have seen them in these species and also 

 in Bombina variegata, and several species of Microhyhdae. This is such 

 a range of Anuran famihes that probably mucous cord microphagy is 

 a general method of feeding in tadpoles. The mucous cords, with 

 entangled food particles, are moved by ciHa towards the wide oeso- 

 phageal funnel, down which they plunge. Sometimes, the cords are 

 tangled in the oesophagus, but in the Microhyhd tadpole, Hypopachus 



