10 
Mr. W. C. Williamson on the Recent 
If then the Lagence be true Foraminifera, the next question is, 
what relationship do they bear to the other organisms of the same 
group ? I apprehend that most if not all the Foraminifera, like 
other Bryozoa, however large and complicated they ultimately 
become, commence their existence as single isolated cells, upon 
or around which others are subsequently built ; some linearly, as 
in Nodosaria and Glandulina; others spirally, as in Rotalina, 
Truncatulina, Rolystomella^ &c. ; whilst others again present va- 
rious modifications of these two types, as Marginulinaj CristeU 
laria, ^pirulma, Quinqueloculina, &c. 
The most simple of the above structures belong to the genera 
Nodosaria and Dentalina, and consist only of a few smooth cells 
piled one upon another with connecting necks. Now a Lagena, 
in its perfect and matured form, must closely resemble the iso- 
lated germinal cell of one of these, exhibiting a phsenomenon, of 
which analogues occur in every department of the organic world. 
It becomes then the most simple and primitive type of the Fora- 
minifera ; bearing in this respect the same relationship to the 
more complex forms that the globule of the Torula or Yeast-plant 
does to Nostoc, Anabaina, &c. amongst the Confervse, and that 
Eunotia does to Fragillaria and young states of the Diatoms 
amongst the Diatomacese. It is another instance of the grada- 
tion, so admirably distinguished by Mr. Lyell and Mr. i\liller *, 
from the erroneous and recently abused doctrines of development 
and progression. 
At the same time that the analogy of form and external con- 
tour thus links the Lagence with Nodosarice and Dentalince, the 
structure of the cell already described appears to indicate a con- 
nexion between them and the genus Eschara and its allies. This 
affinity shows that there are great difficulties in the way of re- 
ceiving any of the existing linear arrangements of these objects, 
and that a new classification will be required, based on a much 
more extended series of observations upon the physiological cha- 
racters of all the genera than we as yet possess. This subject 
presents a wide and interesting field of inquiry for those who 
reside on the sea-coast and have access to these objects in a 
living state. 
The only general fact which remains to be noticed respecting 
tlie Lagence, is the extraordinary capacity for variation which they 
exhibit in different states and ages. Extreme forms which appear 
to be very distinct from one another may be connected together 
by specimens of an intermediate aspect to an extent only to be 
believed by those who examine a large series of specimens side 
by side. I am well aware that the synthetical plan which I have 
* ‘Old Red Sandstone/ by H. Miller, Esq., p. .Vi. 
