528 Howard Edwin Enders, 



cud of the animal. This is probably of use in moving the food- 

 pellets toward the anal end of the intestine. 



The annelids, so far as I was able to determine, behave in the 

 parchment-like tubes as they do in glass tubes of about the same size 

 and form. 



The eggs and spermatozoa are discharged to the exterior through 

 the nephridia. 



The larvae develop a mesotrochal girdle of cilia which is soon suc- 

 ceeded backward by a second and third ciliary girdle while the 

 mesotrochal band becomes atrophied. 



The luminosity which in the adult is associated with the secretion 

 .of mucus is early seen in the larva in the region of the ciliary 

 girdles. 



The "terminal papilla" functions as a hold-fast when the larva 

 comes to rest on some submerged solid. 



Well-fed lar\^£e develop three pairs of eye-spots. This was true 

 of all the larvie taken in the tow-net, but was met less frequently 

 among larvae reared from the eggs. The presence of this number 

 of eyes led Joh. Miiller to name the larvae "Mesotrocha sexoculaia." 



The transformation is a gradual one. That portion of the larva 

 anterior to the second and third ciliary rings becomes the anterior 

 region of the worm. It becomes flattened horizontally and the 

 setigerous somites appear at first as a transversely arranged series 

 of pigment-spots on the ventral side. The post-oral lip enlarges 

 enormously and becomes extended forward as the ventral lip of the 

 worm. Green granules like those of the adult occur in the cells of 

 the entoderm in the middle region of even the youngest larvae col- 

 lected in the tow-net. 



The second and third ciliary girdles mark the first and second 

 somites of the middle region. The former is carried outward by the 

 growth of the 'aliform notopodia and lines the ciliary furrows of 

 these .organs. A portion of the other ciliary girdle persists within 

 the dorsal "accessory feeding-organ." The palettes, the last three 

 somites of the middle region of the worm, are formed by the rapid 

 growth of the dorsal portion of the saucer-shaped somites that lie 

 posterior to the ciliary girdles. This region is succeeded by a very 



