892 THE AMERICAN NATURALIST. | [Vor. XXXIV. 
and two buds (Figs. 2 and 3), present essentially the same 
condition. In these a common stalk bears two bodies united 
side to side, each with its own lophophore, reproductive organs, 
digestive system, nerve center, and budding zones. In serial 
sections of the adult (Fig. 1) I have not detected any essential 
modification of the individual organs. All four of the gonads 
are ovaries. The two immature buds (Figs. 2 and 3) I have 
studied only as entire objects, but could discern no abnormali- 
ties in the different organs. 
A second degree of union is shown by the specimen repre- 
sented in Fig. 4. Here only the lower parts of the stalks are 
Fic. 4. — Dorsal aspect. 4. = bud; /. = flask organ. x 57. 
joined, so that, while the two animals have a common foot, all 
portions of their bodies above the middle of the stalks are quite 
separate and normal. The only abnormality observed in indi- 
vidual organs is in the arrangement of the cells of the dorsal 
row (Fig. 4). Where those of the two individuals come 
together in the fused stalk near the foot, three rows of the 
cells instead of two are present for a short distance, and there 
are slight irregularities in the arrangement of the cells. 
A third condition, represented in Fig. 5, shows a greater 
degree of modification of the individuals and requires a more 
detailed description. The stalk is simple and in no way dif- 
ferent from that of a single individual. From the body arise 
two lophophores, which are quite normal, and bear respectively 
