330 s. HATTA : 



myotome and contains the internal cavity extending likewise 

 for three sections, of Avliich however the hindmost contains the 

 widest cavity, while it is diminished in width anteriorly : in other 

 words, the width of the cavity enlarges in inverse direction 

 as compared with that in the preceding two somites. The 

 Anlage fourth under the seventh myotome (figs. 45 and 46, a.pn. 

 4) has an oval outline like that shown in fig. 26 and encloses 

 an internal cavity, which covers two sections and is anteriorly 

 wide and posteriorly narrow. The two following Anlagen which 

 are detected under the eighth and ninth myotomes respectively 

 (tig. 48, a.pn.ô and tig. 50, a.pn. 6) show almost the same con- 

 dition of development as in the somite just described ; the 

 internal cavity which they contain is likewise extended into two 

 sections ; the width of the cavity is about the same in these two 

 sections, being of a fissure- like form. 



The solid cord which is observed in the embryos of the last 

 stage connecting the Anlagen with one another, is also found 

 here. The cord in the intersomitic plane between the Anlagen 

 first and second (fig. 36, ed.), that between the Anlagen second 

 and third (fig. 40, ed.), and that between the Anlagen third and 

 fourth (fig. 44, ed.) are all comparatively short, so that they 

 are in each stretch confined to only one section, while that in 

 the two posterior intersomitic planes, i.e. between the Anlagen 

 fourth and fifth, and between the Anlagen fifth and sixth, the 

 cord is extended in each case into four sections. In this latter 

 part, the cord is in a primitive condition ; the component cells 

 are actively multiplying. Hence these four sections all show 

 similar features. I have endeavoured to show in fig. 47 one of 

 these sections which is taken from one of the four sections between 



