STRUCTURE AND DEVELOPMENT OF LOXOSOMA. 327 
their cavity widening. They form the deeper part of the 
vestibule, the suboesophageal ganglia arising as a pair of thick- 
enings of their floor. The wings of the crescent-shaped brain 
meet the suboesophageal ganglia at the sides of the oesophagus, 
thereby establishing a complete circumoesophageal nervous 
ring. 
9. After the commencement of the free life (L. Leptoclini) 
no fixation was observed ; the larva, however, developed a pair 
of buds similar to those of the adult. These buds are situated 
at the sides of the dorsal organ, but are quite distinct from it; 
they are visible as epiblastic thickenings long before the 
embryo is ready to be hatched. 
10. The stomach, before the larva becomes free, seems to 
bud off paired lateral bands of cells (L. Leptoclini). During 
the free life these increase in number, and the cells of 
the stomach themselves divide up during an atrophy of its 
lumen. This, no doubt, indicates the approaching death of 
the larva, after the buds have reached maturity. Some of the 
hypoblast cells, whose origin has been just described, probably 
form the endodermic tissues of the bud. 
11. The Entoprocta, larval and adult, are true Trocho- 
spheres, possessing a ventral flexure of the alimentary 
canal, no true body cavity, and a pair of head-kidneys. 
12. The nervous system of Loxosoma develops in almost 
exactly the same manner as that of Dental ium, in which the 
brain arises by invagination (paired), the pedal ganglia as thick- 
enings of the epiblast ; the connection between these two 
independently developed parts is secondarily set up as in 
Loxosoma. 
13. The metamorphosis of the Ectoprocta is to be re- 
garded as a process of budding. Cyphonautes and Tendra 
probably supply important evidence with regard to the 
derivation of the larvae of Ectoprocta from those of 
Entoprocta. 
14. The Entoprocta, being true Trochospheres, have certain 
affinities with Actinotrocha ; there is every evidence that 
the direction of the gut-flexure differs from that of the adult 
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