464 OBSERVATIONS ON THE ANIMALS 
bers, and possesses perhaps hardly sufficient interest to reward the cu- 
rious reader for the labour of perusal. Would that it were other- 
wise! Would that any exertions of ours were sufficient to put for- 
ward in its course this most unattractive, although most useful, 
work. 
It was mentioned, at the commencement of our remarks on these 
Foraminifera, that the species were, for the most part, extremely 
small. No means of judging of the size was, however, given ; and 
to those who have not before studied the subject at all, it will, 
doubtless, excite astonishment when they learn that this minuteness 
is sometimes that of a grain of sand, sometimes a mere point, in 
which no organic structure can be at all recognised by the unassisted 
eye, but never in any instance, except that of the Nummulite, offers 
a surface for examination so large asa grain of Indian corn. Com- 
monly the size is about that of the small [o] in the type before the 
reader; and it is more frequently less than greater. The difficulty 
of managing such very minute objects, and determining accurately 
their structure, both external and internal, will be appreciated only 
by persons accustomed to delicate microscopic investigations. To 
others it must be sufficient to put the facts before them, and Jeave 
them to wonder at the patience and quiet industry of the one or two 
who have devoted long years to the improvement of science in this 
department. 
It must not be concealed that—after all the laborious investigation 
of M. D’Orbigny, and the conclusions to which he arrived after a very 
long series of actual observations by the sea-side—some naturalists 
have denied that the animals of all of these shells are really cepha- 
lopodous. Many of them, so small as to be found clustering round 
the minute branches of sea-weeds, are there fixed, either by the vo- 
luntary act of the animal, or by the adhesion of the shell itself ; not, 
indeed, that the shell actually touches the body to which it is affixed, 
for it is always, as we have said, internal : but in this latter case the 
skin-like covering, or sac, which contains the animal, is the only sub- 
stance that intervenes. In these genera, the organization must, un- 
doubtedly, differ very widely from the type of the Cephalopoda, 
whose structure is far more complicated than is met with in animals 
deprived of all power of locomotion: and unless accurate and minute 
anatomical research absolutely demands their being retained in this 
class, they certainly can hardly be considered as belonging to it. 
With regard to the use of the shell in the Foraminifera, all that can 
be said at present is, that it acts most probably as a float ; and in this 
way may be peculiarly useful to cephalopodous animals, from its 
