89 
tubular branches. These might at first sight be set down 
as very much rolled and worn specimens of the ordinary P. 
tubulosa, but there is no evidence in the Dogs Bay sand of 
other kinds of foraminifera being worn to the extent which 
would be necessary to produce such a result, and the 
suggestion is uncalled for in this particular case since it is 
evident that at one part of the life of the animal its shell 
must have presented the appearance of these specimens, 
unless it could be admitted that the holes are formed after 
the production of the shell-covering on the expanded pseu- 
dopodia. But this last is clearly a single act, and its plan 
is evidently not such as would be adopted if the protection 
of sarcode were the object in view, the subdivision into 
many projecting branches most delicate and fragile at their 
points exposing it as much as possible to every injury ; and 
therefore presenting a form and arrangement not at all 
likely to promote the comfort and convenience of the animal 
if it were to exist long in that state ; and when to this we 
add that the pseudopodia, which are the means by which 
the foraminifera communicate with the external world, are 
sheathed by their shell-covering so as to be incapable of 
action, and moreover that every part of the animal becomes 
completely enclosed, the conclusion seems inevitable that 
this is not a condition in which it passes any considerable 
portion of its life, but that it is, as already suggested, 
merely the closing and final act. The holes through the 
thick shell however present a different history, they show 
by the quantity of shell-material removed and by the way 
in which separate holes have run together, that time has 
been spent in their formation, and they have also a clear 
and intelligible use in the economy of the animal, this 
being to open free communications between the internal 
and external sarcode. As to the process by which the 
shell-matter is removed it seems impossible under the cir- 
cumstances to suppose it done in any other way than by 
