ANTHOZOA HYDROIDA. 87 
Sir J. G. Dalyell, in his most valuable work on ‘the rare 
and remarkable animals of Scotland,” follows out at greater 
length his observations recorded in the ‘ New Philosophical 
Journal.’ “ Nothing,” he observes, ‘‘ can be more remark- 
able to the spectator than finding the progeny free while 
the parent is immoveably fixed—sufficient evidence that 
there is nothing of vegetable nature in such zoophytes. It 
is as strictly an animal product as an Aleyoniwm or an Aser- 
dia, whose original corpusculum, planula, spinula, larva (by 
whatever name it may be called), which by nature becomes 
riveted to some solid sustaining foundation. The nascent 
Tubularia thus formed, and capable of selecting its position, 
loses that faculty never to be regained, and is rooted at an 
indefinite period—sometimes in the course of one day, some- 
times on the lapse of two. But quiescence is essential here. 
Should frequent disturbance alter its place, the adhesive 
power seems to be impaired, or the creature rendered incapa- 
ble of its exercise. The movement of those that are rooted in 
early age is commonly much more rapid than that of others. 
Specimens discharged from the cyst on the 1st of January, 
and affixing speedily, were about four lines high in seven 
days. Those whose adhesion had not ensued were infinitely 
smaller. With the latter it is not improbable that, instead of 
