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constitutional relation ; for in historic times has the medusa-form 
developed out of the hydra-form. Yes, even at the present day, 
the majority of medusze arise directly from polyps. From the 
stomach-wall of the little hydra-like sea-polyp proceeds a bud 
which gradually shapes itself into a medusa, and later on falls off 
like the ripe fruit of a tree, and swims about free. From the eggs 
however of this medusa there do not again arise other meduse, 
but polyps—germs which becoming stationary grow into hydra-like 
cups. 
Yet further in another relation is the remarkable class of 
hydra-medusz of the highest interest for our comparative soul- 
study. For out of it have developed the wonderful Siphonophora ; 
those swimming animal-steps which for the study of the avision of 
labour are so extraordinarily important. The siphonophora are 
found swimming on the smooth mirror of the warmer seas, though 
only at certain times and not abundantly. They belong to the 
most splendid forms of the inexhaustible riches of Nature, and 
whoever has once had the good fortune attentively to observe living 
siphonophora, will never forget the noble sight of their wonderful 
forms and movements. They may be best compared to swim- 
ming flower-stems, whose variegated leaves flowers and fruits 
are delicately formed, tenderly coloured, and shaped like polished 
crystal. Each single flower-like, or fruit-shaped appendage of the 
swimming stem is really a medusa-individual. The various medusz 
of the society have assumed however, through division of labour, 
totally different forms. One part of these medusz has to do only 
with the movement of swimming, another with the reception of 
nourishment and digestion, a third with sensory perception, a 
fourth with defence and attack, a fifth with egg-making, &c. The 
various life tasks which a single ordinary medusa fulfils for itself 
are therefore here divided among the different persons of the 
society, and these have all transformed their bodies correspondently 
to their special life-task. 
In like manner as in the ant-republic, so here also in that ot 
siphonophora, many variously-formed animals of one sort are 
united into a higher social community. But whilst in the higher- 
