THE HYBItOID MEDUSAE. 
345 
strikingly manifested in the complex ramification and the many 
polypites of its plant-like colonies. 
Besides the changes that have been enumerated, others occur 
in the digestive sac, which sometimes attains an extraordinary 
development in the adult, and can be extended far beyond the 
opening of the swimming-bell (Plate LXXXVIII., fig 4). In 
one genus ( Syncoryne ) it stretches out to two or three times the 
length of the body, and is capable of the most active movement. 
This remarkable development of the stomach is accompanied 
by a voracious appetite. 
It is of this form that Edward Forbes writes : “ An animal 
that can pout out its mouth twice the length of its body, and 
stretch its stomach to corresponding dimensions, must indeed 
be 6 a Triton among the minnows,’ and a very terrific one too. 
Yet is this ferocious creature one of the most delicate and 
graceful of the inhabitants of the ocean — a very model of 
tenderness and elegance.” 
Reproduction by budding is a familiar fact in the history of 
the zoophyte, and it enters into that of the free as well as of the 
fixed element. Some of the medusae produce buds which 
assume the form of the parent, and probably repeat its life. 
They are borne in various positions ; in some cases springing 
from the bulbous bases of the tentacles, or from the tentacle 
itself ; in others from the base of the digestive sac ; and in one 
instance, at least, from the margin of the bell between the ten- 
tacles. And these buds may themselves produce other buds, so 
that two generations may hang from the body of the primary 
zooid before its separation from the parent stock. Development 
takes place rapidly ; three or four days suffice for the completion 
of a brood, and before it is mature it is itself budding. We do 
not know the limits of this process, but the number of genera- 
tions originated by a single medusa is probably very great. 
With these facts before us, we cease to marvel at the myriads 
of these organisms that swim in certain seasons near the sur- 
face of the sea. Indeed, apart from this reproduction by bud- 
ding, which has only been noticed in certain species (though 
probably it is commoner than we suppose), there is ample pro- 
vision for an abundant supply of these “ floating nurseries.” 
They are cast off in incalculable numbers from the hydroid 
colonies. In some species each polypite bears a brood ; in 
others each shoot is laden throughout with graceful urns, in 
which not a single medusa, but a whole tribe, is nurtured. 
Probably there may be more than one brood in a season. Then 
consider the immense acreage of the zoophyte crop on the 
shore and the sea-bed, the forests that overspread the algae, 
the populations that hide in well-nigh every chink and cranny, 
and plant themselves on almost every spot where they can get 
