188 ERNEST WARREN. 



thinnest cuticle-like layer (text-fig. 3, a, c). An examina- 

 tion of a reticulum and its growing apices clearly shows that 

 the lateral off-shoots are capable of fusing with neighbouring 

 stolons, the perisarc ultimately disappearing at the place of 

 contact, and the lumen of the lateral shoot becoming con- 

 tiuuous with that of the stolon to which it has joined. In 

 the annexed figure a piece of the stolon reticulum is 

 shown. In the case of the shoot A, the outgrowth has bent 

 round and fused with the parent stolon. In B, a cross- 

 filament is flattening itself over a neighbouring stolon, pre- 

 paratory to complete fusion and the disappearance of the 

 intervening layer of perisarc. C and C are young buds 



Text-fig. 1. 



AA. Branch uniting to parent stolon, c. Young buds covered by thin 

 membrane, b. Young bud fastening itself to neighbouring stolon. 

 X 20. 



which have recently appeared. It is doubtful whether the 

 substance of the perisarc is the same as that of the chitin of 

 Arthropods ; but in any case it is a peculiarly insoluble sub- 

 stance, and it might be of interest to endeavour to trace the 

 mode of absorption of the perisarc in the formation of buds, 

 and the fusion of lateral shoots, since it is clearly not merely 

 a mechanical rupture. I have not, however, had an 

 opportunity to investigate the matter with any thoroughness. 

 The stolons may be knarled in places, and the general 

 contour tends to be somewhat irregular (PI. XXXIII, fig. 2, k). 

 The stems bearing the hydranths are irregularly ringed or 

 spirally ridged to a vai-iable extent. The ridging (r.) may 

 extend throughout the whole length ; but it is generally con- 

 fined to the basal regiou, where the hydrocaulus springs 



