102 DR. THOMAS ALCOCK ON THE 



matter having been lately voided. The rudiments of the 

 hind limbs continued small. The back was beautifully 

 spangled with gold. 



Plate X. 



33. A drawing was made of the ventral surface of a 

 tadpole. It agreed in every respect with that made on the 

 31st day. 



34. A living tadpole was examined under the microscope 

 with a two-thirds object-glass. The water contained great 

 numbers of monads ; and by watching them, it was seen 

 that a strong steady current set in through each nostril, 

 and a corresponding stream passed out through the opening 

 of the gill-chambers at the left side of the body. 



A drawing was made of the outlet from the gill-cham- 

 bers. The nostrils had the form of short wide projecting 

 tubes. 



34 (2). The gold spangles were perfectly metallic in 

 appearance ; and their angular irregular shapes exactly 

 imitated small bits of gold leaf. Sketches of three of 

 them were made. 



35. A drawing was made of the ventral surface of a tad- 

 pole, inclining to the right side and viewed by transmitted 

 light. It showed nothing new, but gave good representa- 

 tions of the mouth and the rudiment of the right hind 

 limb. 



36. A tadpole was killed, and the gold spangles on the 

 back examined. They were much smaller than before, and 

 more numerous : almost all of them were in pairs ; but 

 occasionally there were three in a row. Sketches were 

 made of them. 



37th. On the back of a tadpole examined today the 

 gold spangles were again smaller than before, and were in 

 groups of three or four instead of in pairs. The rudiments 



