292 J. H. ASHWORTH. 



1. The buds arise in connection with that portion of the 

 superficial endodermic canal system situated at the edge of the 

 summit of the stem. When a bud is about to be formed, the 

 superficial canal becomes enlarged and the outer wall of the 

 canal becomes pusiied outvvards towards the surface of the 

 stem. This produces a small tubercle upon or immediately 

 under the edge of the expanded end of the stem. The 

 tubercle increases in size, and its distal end soon becomes 

 divided into eiglit small pouches which become the tentacles 

 of the polyp (PI. 24, fig. 4). The divisions between the 

 pouches are the mesenteries of the polyp, and they gradually 

 grow inwards into the coelenteron. The eight mesenteries are 

 already formed in the young polyp shown in fig. 4. 



In the centre of the free end of the bud there is a slight 

 depression, and a small darker area which marks the position 

 of the future mouth (fig. 4, Mo.), and also the ingrowing plug 

 of ectoderm which forms the stomodseum. Sections of this 

 bud show that the stomodeeum is '14 mm. long, and rather 

 flattened laterally. Its oral end is still solid, but the inner 

 portion has become tubular, and its cavity opens into the 

 coelenteron of the polyp. The distance from the depression 

 indicating the position of the mouth to the innermost portion 

 of the coelenteron is "4 mm. Mesenteries are distinguishable 

 only in the npper three fifths of the coelenteron. In other 

 respects this polyp resembles the one described below, and 

 drawn in fig. 28. 



2. A slightly older polyp (No. II in table, p. 284, and drawn 

 in section, fig. 28), '43 mm. long, possesses tentacles which are 

 not all of the same size. The dorsal and ventral ones are 

 largest (about "12 mm. long), the two lateral ones a little 

 smaller, and the remaining four still smaller. These differ- 

 ences in size are very well seen in transverse sections through 

 the polyp at the level of the mouth. A second specimen of 

 the same size was cut longitudinally, and shows several inter- 

 esting points (fig. 28). The stomodseum is about "32 mm. 

 long, and is tubular along the greater part of its length. The 

 mouth is, however, closed [)artly by approximation of the walls 



