46 C. M. CHILD. 



(c) Oblique Lateral Incisions Dircctea Orany. 

 When the oblique incision is directed orally the results differ, 

 according to the angle as in the case of aborally directed incisions 

 described in the preceding section. If the angle between the 

 incision and the transverse plane is not greater than 30-40 'y.., 

 Fig. 13) a lateral partial disc with mouth is usually formed, the 

 parts distal to it atrophy and it gradually migrates to the oral 

 end of the body. The sequence of tentacle-formation in these 

 partial discs is that characteristic of other oblique discs, the 

 tentacles appearing earliest on the two opposite ends of the 

 partial disc, which in these cases are the most distal portions, 

 and latest on the middle, most proximal portion. 



When the orally directed incision is more oblique, however 

 {e. Fig. 13) other results are obtained. In most cases of this 

 sort complete closure of the wound occurred sooner or later with- 

 out the formation of a lateral mouth or partial disc, /. e., the cut 

 margins of the body-wall united longitudinally with each other 

 and not with the cesophagus, and the oblique slip, which in 

 these cases is directed aborally, formed a small shrivelled excres- 

 cence, which underwent gradual atrophy and resorption. 



After these incisions the margins of the body-wall approximate 

 and unite longitudinally from the proximal end of the cut distally 

 (Fig. 20, the area of new tissue is indicated by shading). When 

 the approximation of the margins and the accumulation of slime 

 has brought about a provisional closure and partial distension is 

 possible, the more distal portions of the cut margin are pressed 

 against the aborally directed slip which overlaps this region and 

 union readily occurs here, so that the whole wound is closed 

 without the formation of a disc. Here the result, in itself 

 different from that obtained with aborally directed oblique in- 

 cisions, is brought about by the same internal factors, /. e., the 

 characteristic reactions of the species, but the conditions under 

 which the reactions occur are different, hence the difference in 

 result. In the case of aborally directed incisions the partial dis- 

 tension separates the oblique slip from the rest of the body-wall, 

 since the sHp shares more fully in the distension than the portion 

 of the body-wall directly distal to the cut. In the present case, 

 on the other hand, the oblique slip is less distended than other 



