REDFERN, ON FLUSTRELLA HISPIDA. 101 
striated mass, and on the third day it had become much 
more distinct, whilst the gemma appeared to be encroaching 
on the old cell, and the striated mass had approached the 
surface (fig. 13). Witha view of facilitating the examination, 
a small mirror, the framework of which had been recently 
coated with gold size, was introduced into the aquarium. 
Shortly afterwards, the tentacles of the polypide (fig. 11) 
were observed to be bent at various angles, and to hang 
loosely, as if they had been broken, resuming thei natural 
appearance at intervals. The polypide protruded itself but 
rarely, and never recovered its healthy characters, dying four 
days subsequently. I believe that it was injured by the 
gold size. 
On the fourth day of the formation of the gemma, it pre- 
sented a yellowish striated band at its deepest part, appa- 
rently the first trace of its retractor muscle. On the same 
day, traces of the formation of three other gemmee were seen, 
as in fig. 14, but their development was speedily arrested, and 
they were not again observed. 
On the seventh day, the new polypide presented the form 
of a bent tube, the striation near the surface remained, and 
between it and the bent canal, representing the body of the 
animal, there was a clear space faintly separated into bands 
by indistinct striz (fig. 15). These ultimately became the 
tentacles. On this day, four distinct and blunt hairs were 
observed to have formed on the wall of the cell of the new 
polypide. 
On the eleventh day, the gemma had considerably in- 
creased in size, and presented a nipple-like membranous 
prominence. The polypide was observed shrinking in its 
cell on the application of a bright light. The hairs, which 
were blunt at their ends on the seventh day, had become 
pointed. The perigastric space was quite distinct. The re- 
fractive globules, producing the striation near the surface 
had gradually diminished in number, and formed a thin 
layer between the tentacles and the surface. This state was 
figured on the twelfth day, as in fig. 16. 
On the thirteenth day, the apex of the cell had become 
much thinner, and presented the appearances represented in 
the drawings (figs. 17 and 18), sketched by the aid of the 
camera lucida, when the polypide was retracted and protruded. 
The tentacles were much longer and more distinct, the rows 
of highly refractive globules between the tentacles and the 
surface were greatly diminished in number and size, and the 
perigastric space was clearer. The condition of the polypide 
at this timeis so graphically described by the Rev. T. Hincks, 
