480 Leland Griggs. 



VII. Neuromeres appear behind the procephalic lobes but 

 owing to the fact that they are irregular and quickly disappear 

 their history cannot be followed. 



VIII. The anlage of the lateral eye and the anlage of its 

 ganglion, the optic lobes, are seen lying lateral to the neural axis 

 before the closing of the tube. The optic lobes form the roof 

 and sides of the mid-brain. 



IX. The neural crests first close together just in front of the 

 anus, then coalesce slightly at the anterior end, then meet over 

 the procephalic lobes. From these points fusion proceeds in 

 both directions. 



X. The anterior neuropore remains open for a very short 

 time. 



XL The anlage of the ear is pigmented. 



XII. The division of the closed neural tube into a series of 

 swellings is present in Amblystoma but these divisions do not 

 correspond exactly to the true neuromeres of the open plate. 



XIII. Since the cerebellar swelling is found at the sides of 

 the fourth neuromere of the procephalic lobes, evidently these 

 lobes occupy a region corresponding to the fore-brain, mid- 

 brain and a portion of the hind-brain. 



