252 Proceedings of the Royal Physical Society. 
see their beautifully chambered shells imitating some of the 
most graceful objects of nature and art, — the living streams 
of nearly fluid sarcode, of which they are composed, flowing 
forth from the almost invisible pores of their shells, uniting 
with each other, and forming glairy masses, and reticula- 
tions, and expansions, which absorb animal matter coming 
in contact with them, — single and compound animals build- 
ing their aggregated homes in the most graceful lines and 
spirals, — single dwellings and populous towns slowly moving 
along, of which the inhabitants are but patches of transpa- 
rent slime, — vast Polythalamian cities, where the huge pri- 
mordial Ehizopods reign, surrounded by the multitudes of 
their dwarfed descendants, in widening circles and triple tiers. 
Such is Khizopod life. At present no true generative ele- 
ments have been recorded as discovered in the Ehizopods, 
though Carpenter and Schultze have noticed bodies whicli 
they have suspected to be ova. In the autumn of 1859 I 
was preparing a number of specimens of Hydractinia for the 
microscope. They were first soaked in whisky for several 
weeks, then immersed in dilute nitric acid to remove them 
from the crab's shell, and finally washed in strong spirit, 
and put up in Canada balsam. On examining one of these 
preparations under the microscope, it was found that two 
specimens of Truncatulina had been accidentally prepared 
at the same time. The development of Truncatulina com- 
mences with a single cell ; this multiplies by gemmation in 
series until a colony of animals is formed, each larger than 
its predecessor, arranged in a spiral, somewhat resembling 
the shell of the Nautilus. In the Nautilus, the last chamber 
of the shell only is occupied ; but in Truncatulina every 
chamber contains its tenant, while the whole colony are 
united by a band of sarcode, which passes from chamber to 
chamber along the inner curvature of the shell. All the 
cells or houses in this Khizopod town are full of minute 
pores, from which the inhabitants protrude their delicate 
arms of slime in search of prey, or to move the assemblage 
from place to place. When the Truncatulina is treated as 
before mentioned, the shell is removed, and the separate 
zooids appear united by their connecting band. One of the 
