ted bud it is generally the distal end that is the more acute. 

 This is also tn^e of the poste>"ior end of the S'vimming larva, 

 in which the mouth always arises. Better evidence is fur- 

 nished, in the second place, by the position of the septal mus- 

 cles. It is known that in larvae produced from eggs the sep- 

 tal muscles arise as ingrowths from the ectodenn of the peris- 

 tome. In the buds of Oassiopea the septal muscles when fii'st 

 observed have the appearance of ingrowths from the ectoden^i of i 

 the distal end of the bud, and it is impossible, at this time, 

 to trace them to the proximal end. The earliest sta^;e after 

 the formation of the mouth of v;hich I have sections, has the 

 septal muscles continuous with the ectoderm of the peristome 

 in the same v/ay. Compare Figs. 28 and 31. 



This seems conclusive, but, on the other hand, the fact ■ 

 must not be overlooked that in the stage last mentioned the 

 septal muscles are also well developed in the aboral end of the 

 larva. Moreover, in the bud when about to be set free, while 

 the entoderm cells in the proximal part are somewhat granular, 

 those on the distal end are clear and larger than the others, 

 and thus come to be more like the entoderm in the stem of the 

 scyphistoma. Fig. 29. This is directly opposed to v/hat is 

 indicated by the origin of the muscles and makes it possible, 

 therefore, that the distal end of the bud may, after all, be 



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