5r)4 T. TKEDA : 



tion situated in front of tlio moutli and just under the ganglion. 

 It is called the " suhneural gland." Here again I am not in a 

 position to confirm his view. In spite of repeated examinations 

 on living sjiecimens, I have heen unahle to discover any structure 

 which has the slightest resemhlance t(^ the sul)neural gland. To 

 judge from my own ol^servntion, the " sul)ueural gland " as well 

 as hoth the " oral-" and the '' pharyngeal grooves " of this author 

 are products of his fixing method. In preserved specimens, it is 

 fi'equently noticed tliat the lower wall of the hood is hulged out 

 and downwards in front of the mouth (fig. K), prom.), and, as a, 

 result of this, there is hrought ahout on the wall behind the 

 prominence a depression, which appears on sections as a tolerably 

 deep pit (fig. ()3 a). 



Sloiiiach. The stomach forms the largest and widest portion 

 of the alimentary canal. It is especially long in the larvie of type 

 I), in which it extends l)elow nearly to the plane of the perianal 

 l)elt. Tlie greater part of the stomach wall is composed of 

 cylindrical cells with short cilia whose spherical nucleus is usually 

 situated in the centre of the cell (figs. 45, 48, and oO a, dow.). 

 But the anterior portion of the wall along the mid-doi'sal line and 

 the posterior portion iiear the intestine greatly differ in their 

 constituent cells from the remaining parts. They consist exclu- 

 sively of tall ciliated cells which contain elongated nuclei, and 

 are, in a word, of the tpso])hageal type (fig. 45). In the full 

 gi'own larva, the ventro-latei'al portions of the stomach wall form 

 two digestive areas placed in the neighbourhood of the septum. 

 Here the cell boundaries are indistinct and the nuclei are im- 

 bedded in a common mass of protoplasm, in which remains of 

 various unicellular organisms ai'e enclosed. 



From the anterior end of the stomach a pretty wide and 



