INTRODUCTION. 



XX XV 11 



thin partition, present the appearance of a single sub- 

 globular collection of granules (Woodcut, fig. xv. ek). 

 The cord traversing one compartment is linked to that of 



Fig. xv. 



L'teitostoiiiatuns stem. 



ft. Stem. br. Brunches, s. Septa, at the origin of the branches. 

 ec. Eudosarcal cord. tk. Endosarcal knot. 



the next by a thread-like extension of its substance, 

 which passes through the pore or pores in the septum. 

 Not unfrequently the cord gives off from its surface a 

 number of filamentary processes, which sometimes ana- 

 stomose, and sometimes pass directly to various points on 

 the wall of the tube, the whole forming a rude network 

 of fibres, or plexus. This portion of the structure is very 

 irregular and variable, and, according to Joliet's observa- 

 tions, is liable to frequent change and modification *. 



* Dunn 1'espaee de peu de jours une portion du plexus s'est modiflee 

 sensible-meat sous mes yeux, puisque j'ai vu un de sea rameuux s'atrophier 

 ci di-]i ir.iitre totalement." The foregoing account of the funicular system 

 is based chiefly on the researches of Joliet('Bryozoaires dee cotes de France') 

 which I -.in 'iitirm in most points from my own personal observation. 



