654 
SCANDINAVIAN FISHES. 
When she has thus collected the troop around her, she 
suddenly deals a blow that scatters the whole crowd 
in an instant. This sport is often repeated, but the 
rapidity with which they disperse, renders it impossible 
to observe whether it is always the same female that 
takes the lead, or whether they change places. These 
operations are continued, as long as the sun is high 
Fig. 163. Male of Gasterosteus ciculeatus in front of its nest. 
Natural size. 
in the heavens, for 4 — 6 days, according to the weather. 
It seems more than probable that during these evolu- 
tions the females lose some roe, which adheres to water- 
plants, and that this is fertilized by the males that, 
perhaps only for the time being, have not built any 
nest for the eggs. Benecke has also ascertained that 
under certain circumstances, as for example when he 
finds a suitable crevice or secluded nook among the 
water-plants, the male does not build any nest properly 
so called. Thus we have to deal with two methods of 
spawning, the free spawning, in which the eggs are 
developed where they fall, among the water-plants, and 
the more connubial method, in which the eggs are de- 
veloped in a nest built by the male. But in any case 
the nest-building is one of the most interesting parts 
of the life of the Three-spined Stickleback, and one 
which many have been in a position to observe (fig. 163). 
The earliest account we possess of the nest-building 
of the Sticklebacks is nearly two hundred years old. 
In 1721 the English writer Richard Bradley tells 
us" that one Sergeant Hall had seen a Stickleback 
build a nest, and had secured the latter in order to 
present it to Bradley, who gives a figure of it and 
says that he “supposes it was rather composed to lav 
the spawn in, than for a lodgment for the fish itself." 
Since that date several naturalists have watched the 
building operations of the male Three-spined Stickle- 
back in its native haunts; but the most accurate ob- 
servations of its habits have been made in aquaria, 
where the Three-spined Stickleback constructs its dwell- 
ing in the same way as when at liberty. Brehm has 
described its method of building in his work on The 
Life of Animals b as follows: 
“Warrington®, CostfT, and Evers have observed 
their captive specimens at work. During the spawning- 
season, as we have mentioned, the male wears a dress 
of the most gorgeous colours, and lie displays his en- 
hanced activity and vivacity in other ways as well. As 
soon as he has decided on a certain spot at the bottom, 
he first drags together some roots and other parts of 
several aquatic plants. These pieces may be larger than 
himself, and are often fetched from considerable distances. 
With great pains he tears off comparatively large bits 
even from living plants, tests their weight by letting 
them fall to the bottom, and employs in his work only 
those that sink quickly, rejecting all that prove too light. 
The building-materials are thus carefully selected, piled, 
and still further adjusted, until the little architect finds 
them arranged according to his wishes. To attach the 
nest to the bottom he employs sand or small pebbles®. 
“ A Philosophical Account of the Works of Nature , p. 61, pi. VIII, fig. II. It may be questioned, however, whether this nest be- 
longed to the Three spined Stickleback or to the following species. 
b Thierleben. 2:te Aufl., 3:te Abth., 2:te Bd., p. 88. 
c Ann., Mag. Nat. Hist. 2nd ser., vol. X, p. 27 6. 
d Mem. Sav. Etrang. Inst. Fr., tome X (1848), p. 575. 
e The Three-spined Stickleback may also build its nest above the bottom and among the branches of the water-plants, though 
this method of building seems to be more characteristic of the next species. 
