104 DR. THOMAS ALCOCK ON THE 



the rudiment of the hind limb in the same condition as 

 when last represented (on the 35th day). 



The whole of the upper surface of the body of this tad- 

 pole was covered with gold spangles ; they were small but 

 very numerous, and were often arranged in groups of four, 

 forming a square ; and sometimes four or five were near 

 together in a line. The spangles on the under surface of 

 the body, which were fewer in number, were like silver. 

 The muscular middle part of the tail was thickly covered 

 with stellate marks of black pigment; a few were also 

 scattered over other parts. 



49. One of the largest tadpoles from the basin was killed, 

 and a drawing made of its mouth with a two-thirds object- 

 glass under the microscope. It was placed rather side- 

 ways ; and the lower lip was not everted ; so that, although 

 the whole of the details were not fully shown, it gave a 

 natural view. The lips and the teeth upon them are fitted 

 for holding food, and the strong serrated beaks for biting. 



51. A tadpole from the pond was examined living. 

 Water was seen to flow in through the nostrils, and out 

 from the opening at the left side of the body. The gold 

 spangles were small and distributed in clusters of perhaps 

 a score in a patch. 



A drawing was made of the right hind limb (51). De- 

 velopment had commenced ; the limb was short and thick, 

 contracted slightly at the ankle and club-shaped at the 

 end ; its shape was something like that of a horse's foot. 



53. An outline drawing of a large tadpole from the pond 

 was made, of the natural size. 



Plate XII. 



Two drawings were made, one of the left, 53 (2), the 

 other of the right, 53 (3), hind limb of a tadpole from the 

 pond. They showed an advance from the former state, 



