304 CHORDATA. 
Amphiorus is dicecious. The gonads lie as a paired 
lateral row of organs just inside the ventral 
longitudinal muscles. They are said to have 
no ducts and to burst into the atrium when ripe. 
Reproductive. 
Fig. 218.—THE DEVELOPMENT OF AMPHIOXUS AS SEEN IN LonGI- 
TUDINAL SECTION AND LATERAL VIEW or LARVé. 
Notochordal 
Hypoblast. 
Blastopore. 
Notcchord. Neuropore. 
Blastopore { 
Neurenteric 
saqTUIOS 
o1se[qose yl 
Neural Tube. Neuropore. 
Notochord. 
Anterior Meso- 
blastic Sac. 
1 Collar-sac, followed by 
8 the Mesoblastic Somites. 
A, Blastula. B, Gastrula. C, Completed Gastrula. D, Commencing Neural Tube. 
E and F, Lateral view ’ of later chordula stages. (After HATSCHEK.) 
