POLYZOA AND TUNICATA. 
229 
and ever merging into one another. Now this would be 
very puzzling ; and it would not be till after a great deal 
of examination in detail, and a great deal of “ putting 
two and two together,” and many happy guesses, that 
he would at length master the idea of a quincuncial 
plan — the order of a not. 
But suppose that the net, instead of being woven on a 
single plane, as all our nets are formed, were made to in- 
crease in every possible direction — a not to be estimated 
by solid instead of superficial measure, like the colls which 
go to make up the pulp of an apple — how would the 
plan be complicated ! And how much more of protracted 
observation and study would be necessary before the in- 
quirer could master this model by the slow study of a 
bead at a time ! 
Now, we do not mean to say that the great plan of 
Creation can be correctly represented by a series of 
meshes in a plane, nor by a mass of cells in a solid, nor 
by circles set circularly till a larger circle is formed, and 
many of these set to constitute a still larger circle, and 
then again others still larger; we will not set our seal to 
any of those models, which have been from time to time 
proposed with great confidence as “ the natural system.” 
But the comparison may help some of our readers better 
to appreciate the fact, that while there is a beautiful 
order in creation, the existence of which is readily dis- 
covered, it is an order, not simple, but highly complex in 
its relations. 
A notable example of the breaking down of the linear 
arrangement occurs in a series of creatures which we have 
now to introduce to our readers : a series which, com- 
