ON BUDDING IN ANIMALS. 17 



Loxosoma, which is frequently an ecto parasite of Annelids and 

 Gephyreans, the buds of the larvae arise as a surface-thickening 

 (ectodermic), growing inwards to form the lophophore (Harmer), 

 and in all probability a process of the stomach (hypoblast cells) 

 goes to form the larval digestive system. Loxosoma at a given 

 moment is unisexual, some having small, others large, eggs. In 

 Pedicellina the buds spring from a creeping stolon. By means 

 of ciliated young, which are produced from eggs, the range of 

 the species is greatly extended. An analogous arrangement 

 occurs in the creeping stem of Rhabdopleura, from which the 

 polypides come off at various angles, and which has a remark- 

 able tendency to form buds. The ova of this form are unknown, 

 though Eay Lankester found the testes in the abdomen. 



Still more striking is the condition in Cephalodiscus (a Diplo- 

 chordate of Masterman), one of the most interesting discoveries 

 of the ' Challenger,' for, in addition to its few though large 

 eggs,* it has a furor for budding from the tip of the pedicle, the 

 majority presenting from one to three or more buds at various 

 stages. These buds are first observed as little processes pro- 

 jecting from the hypoderm, and in their earlier stages at least 

 seem to have a channel of communication with the body-cavity 

 of the adult. Moreover, the cavities characteristic of the latter 

 are soon differentiated, viz. the cavity of the shield, the two 

 collar- spaces, and the body-cavity divided by the mesenteries 

 (dorsal and ventral). The small club-shaped bud soon develops 

 a shield, which is proportionally large, with papillae as rudiments 

 of the plumes. The pedicle is short, and has a sucker-like 

 hypodermic projection, and, since a peculiar curvature of the 

 body takes place, the tip of the pedicle scarcely projects beyond 

 the margin of the disc. Shortly after the symmetrical filaments 

 on each side of the plumes are visible (though quite small), the 

 bud separates from the adult, and as soon as — and sometimes 

 even before — it is detached, a little bud appears near the tip of 

 its pedicle. Thus the increase of the species by budding alone 

 is very considerable, even comparatively young forms giving rise 

 to a succession of buds. 



The general form of the Polyzoa would lead us at first sight 



* As in Artisca, in which they produce embryos about a third the size 

 of the adult. 

 Zool. 4th ser. vol. IX., January, 1905. c 



