746 Scientific Proccedings, Royal Dublin Society. 
entire concave surface of the coccolith (fig.2). But in this we 
never were able to detect any marked movement, nor other 
definite sign of life. Neither were we able to observe nucleus nor 
any evident chromatophores. 
Although the free coccoliths are so abundant we were able to 
find but few coccospheres. After many prolonged searches we 
have only come across a half-dozen or so. The coccoliths aggre- 
gated on these presented, as a rule, a much less battered appear-- 
ance than those free in the water—a fact which is suggestive that. 
the coccospheres are the source of the coccoliths. 
The observation of Wallich, that a membranous covering 
envelops the coccosphere,! seemed to us supported by the 
appearance of these bodies. The whole contour is singularly 
spherical, and such that the component coccoliths appear as if 
fitted together, at least partially, by pressure from without. 
Upon treatment with dilute acids the coccospheres dissolved, and 
a globule of pale brown or yellowish proteid matter remained 
behind, agreeing with the observations of Wyville Thomson® 
and others. 
Our observations up to the present are hardly such as to give 
us any advantage over previous observers in forming an opinion 
as to what may be the nature of coccoliths and coccospheres. ‘Two: 
suggestions present themselves. ‘The first, the already well-known 
one, that the primary body is a small and abundant alga, which 
secretes upon its surface the shield-like coccoliths. These, upon 
the death of the coccosphere, are liberated. As will be seen 
further on, other spherical bodies of almost the same dimensions 
are present in the water, and these secrete each characteristic 
forms of investing shields. A class of minute alge (?) should, if 
this suggestion prove true, be recognised which might embrace 
eoccospheres and rhabdospheres, as well as two organisms to be 
described later. 
Or, again, it may transpire that the coccosphere is a reproduc- 
tive stage in the life-history of coccoliths (these latter being inde- 
pendent individuals). The coccosphere might then be regarded 
as somewhat homologous to the plasmodium of the Myxomycetes, 
formed by the adhesion of a number of independent organisms, or 
it may prove rather to represent an auxospore, such as is found in 
1 Ann. and Mag. of Nat. History, 1860. 2 Loc. cit. 
