CASSIOPEA XAMACHANA. 213 



an aquarium at Banyuls in 1892. No strobila or ephyra was observed up to October, 

 1893, but in the meantime the number of scyphistomas had increased enormously. The 

 buds appeared as elevations on the side of large individuals. The base of this elevation 

 became elongated into a filamentous stolon carrying the bud at its tip. The bud fixed 

 itself to the glass, gradually developed tentacles, and finally became independent by the 

 disappearance of the stolon. 



In Cassiopea xamachana the process of budding is an important, if not the chief, factor 

 in the perpetuation of the species. On looking over collections of scyphistomas taken 

 from the Great Salt Pond during May, June, and July, a considerable number was found 

 with buds attached in various stages of development (Figs. 1, 2, and 26), and budding 

 continued in the aquaria. 



There is no stolon. The first visible rudiment of the bud is a slight swelling on one 

 side of the calyx just above where it tapers into the stem. It involves all three layers of 

 the body wall (Fig. 36) . At an early stage in the growth of the bud the four septal 

 muscles may be found as four slender cords of cells embedded in the mesogloea and appar- 

 ently growing out from a thickened area of the ectoderm at the apex of the bud (sm, 

 Figs. 38 and 39) . This appearance seems to indicate that the septal muscles of the bud 

 are formed, as in sexually produced scyphistomas, by an ingrowth of the ectoderm. 



Careful study of serial sections through young buds shows, however, that the 

 septal muscles of the bud are connected with septal muscles of the parent. In 

 Fig. 37 the course of the septal muscles is reconstructed from a series of longi- 

 tudinal sections. The muscle sm t passes around the base of the bud on the side 

 away from the observer and gives rise to two branches, sm\ and sm' 3 . These extend 

 toward the apex of the bud, and each one divides dichotymously. Muscle sm 4 gives 

 off a branch which fuses with sm^ at the base of the bud. Sm 2 produces three branches 

 which unite into a single branch. This branch extends into the base of the bud, but it 

 was impossible to trace it further. It may be connected, perhaps, with the muscle sm' 2 , 

 which was traced for a short distance from the apex of the bud. 



On account of the presence of the muscles, it is possible to study the relation of the 

 plan of symmetry of even young buds with the symmetry of the parent. A series of 

 sections made at right angles to the long axis of the bud shows that the vertical perradii 

 of the bud lie in the plane of one of the perradii of the parent. But in transverse 

 sections it is impossible to trace the muscles of the bud, except for short distances, 

 owing to their extreme fineness. 1 



However, the study of longitudinal sections makes it reasonably certain that the sep- 



1 The position of the bud is always perradial, although in some preparations it appears to be interradial, owing to the 

 obliquity of the sections, as in Fig. 36, 



