30 Mummery on the Development of Tuhularia indivisa. 
differing from the adult, excepting in the number of its ten- 
tacles. Within five minutes after the extrication of the animal 
already described, a second escapes through the dilated mouth 
of the capsule, but differing greatly from the former in con- 
figuration. It closely resembles, in miniature, a young spe- 
cimen of one of the star-fishes {Solaster papposa), presenting 
a discoidal form, surrounded by twelve obtuse tentacles. 
In the course of thirty -six hours this had greatly changed 
in form, and, within a few days after, the two varieties pre- 
sented but slightly different aspects, especially after they had 
fixed themselves. The empty capsule, or ovisac, with its 
contained placental column, remains dilated, exactly as when 
the young animals quitted it. 
After the lapse of about six weeks, the animals, which were 
previously colourless, gradually acquire a pale rose tint around 
the head, and eventually the ovaries are developed as it ap- 
proaches the adult state. 
Much difficulty is experienced in preserving this zoophyte 
in a healthy state for examination, but it may be worth ob- 
serving that I at length succeeded tolerably well by connect- 
ing a syphon of gutta percha with a reservoir of salt water, 
and thus causing a small stream to fall from a height of several 
feet upon the surface of the water containing the specimens, 
and allowing the surplus water to overflow into a larger re- 
ceptacle. The agitation thus produced had the effect of 
retarding the fall of the heads. 
I trust I may be pardoned for referring to the highly in- 
teresting suggestion of Professor Forbes, in his admirable 
treatise on the naked-eyed Medusae, viz. : That possibly all 
the Medusae are, at one period of their life, fixed animals, as 
proved by Sars in the case of Cyanea aurita ; and that, con- 
versely, many of the zoophytes may be found to pass through 
a medium stage of existence, during which the germs are 
developed from which the zoophyte is reproduced, — as in the 
instances of Laomedea and Cyanea. 
As the latter zoophyte presents so close an affinity to the 
subject of my remarks, I have most carefully repeated my 
observations, and feel convinced that the animal which 
escapes from the pedunculated capsule is distinctly trace- 
able through all its stages, until^ when fixed, it becomes 
the adult Tuhularia, and that it undergoes no intermediate 
metamorphosis, or alternation in its mode of existence ; I 
have thought it possible that the eight -armed creature might 
prove a Medusoid. 
