BEFORE THE DAWN OF ART 279 
fans and trumpets, towers and cupolas—what a 
wealth of form there is among these atomies with 
their hundreds of different species! One of the 
many interesting features is that certain of the 
shapes point forward to the shells of Cephalopod 
and Gasteropod mollusks. 
The lime shells of Foraminifera have been familiar 
for many generations, and no one has pretended 
to understand them. They are secreted—simply 
secreted !—by organless individuals, each “a drop of 
protoplasm ” which streams out into the water in a 
changeful network of delicate threads. Some salt 
of lime is absorbed from the sea water; it passes 
through the plasmic laboratory; it is laid down as 
an arabesque of translucent marble. That is all! 
We cannot explain how Globigerina makes its 
beautiful shell any more than we can explain how 
the nightingale makes his song or the poet his epic. 
Indeed, we are intellectually farthest from any 
understanding of the Globigerina’s poem. 
But what prompted us in this discussion had to 
do not with calcareous shells, but with those that 
are built up of extrinsic particles selected from the 
surroundings. It is of the so-called arenaceous 
Foraminifera that Mr. Heron-Allen has such won- 
derful things to tell us, and it is obvious at once that 
the problem is here more accessible—that is to say, 
more readily attacked—by way of experiment, such 
as Mr. Heron-Allen has, we believe, the patience 
and ingenuity to devise. In the case of calcareous 
shells the material that is taken in is invisible; its 
