ON THE RADIO LARI A AS AN ORDER OF THE PROTOZOA. 277 
! 
egg, within which are distributed peripherally, but without any 
approach to regularity, a number of granules of more consoli- 
dated, as well as more or less faintly coloured sarcodic substance 
(fig. 2 a); and invariably (I believe) in the case of the sarcode 
of the oceanic Rhizopods, of a tolerably brilliant yellow tint. 
But by carefully focussing down to an equatorial plane, a central 
portion, altogether devoid of granules, and occupied solely by 
the pure basal sarcode, may quite readily be detected (fig. 2 b). 
It is to this clear portion that the somewhat misleading name of 
nucleus has been applied ; perhaps owing to the idea that its ap- 
parent higher degree of refractive power, as compared with the 
surrounding mass of the animal’s sarcode, may be clue to its being 
a specialized product ; or, in other words, not identical with the 
basal ungranular sarcode of the lfest of the sarcoblast itself, and 
of the general body substance in which granular particles are 
almost always, more or less densely, suspended. Through some 
subtle reproductive operation, of which we as yet have learned 
nothing from actual observation, in consequence of the extremely 
minute nature of the particles concerned, the yellow granules 
become, after a time, collected together into the spheroidal 
masses now become sar coblasts ; and, possibly, two sexual ele- 
ments are, at this stage of the organism’s history, brought into 
contact. It will, I hope, be clearly understood, however, that I 
throw out this view simply as a surmise, resting on no more 
stable basis than a fact observed by myself, and for the accuracy 
of which I am ready to vouch with perfect confidence, that the 
so-called nucleus of the sarcoblast becomes eventually, on the 
escape of that organ from the parent structure, the active centre 
of shell or skeleton-development. But on this subject I shall 
have more to say hereafter. 
We are hence almost irresistibly led to the conclusion that 
the truly constructive 66 germinal ” substance of the Rhizopod 
is the hyaline, homogeneous, viscid, and ungranular portion of 
the sarcode ; whereas the granules and every other portion form- 
ing an integral part of the structure, are developments from 
this, and constitute true “ formed material ” ; this view holding 
good both as regards the entire mass of the body in the youngest 
stage of the naked Amcebans ; in the earliest formed chamber 
of the Foraminifera ; and also in the earliest stages of the 
Polycystina , Plagiacanthidce , Acanthometrina , and Dictyo- 
chidce , in which the siliceous structure constitutes an in- 
ternal framework or skeleton, rather than an external shell. 
Whilst throughout the entire series of the Rhizopodal families, 
wherever there exists a mineral fabric of any kind, whether 
shell, framework, groups of spicules, or shell composed partly 
of mineral matter elaborated by a vital operation of the creature, 
and partly of altogether extraneously derived mineral particles, 
