136 FORMATION OF SHELLS OF ANIMALS, ETC., 
specimen the isolated particles of pigment can be seen 
either scattered about irregularly, or arranged in lines, 
prior to their union to form a corpuscle ; hence these irre- 
gular bodies furnish the same evidence of being formed by 
the union and coalescence of pre-existing particles, as the 
irregular stellate earthy bodies before noticed in shells 
and bone do. Whilst there is nothing in their appear- 
ance which can give the least semblance of probability 
to the generally received opinion that the branched and 
dotted lines, as represented in the figure, are offsets or 
shoots from a central formative organ or cell-germ. I 
may observe that I have the specimens from which the 
Fic. 9. drawing was taken, and that 
~ similar ones can easily be 
oe obtained from very young 
ene “eghonns? animals, especially from rep- 
ee ele len ‘ tiles and fish, and from the 
one git Alita lao hus choroid coat of foetal mam- 
jal 0a > (Ce = mals. Also examples of 
Thr et hd ne molecular coalescence in the 
un ey softer tissues, equally strik- 
oe if ing, can be seen in the 
Oeste developing -hooklets of the 
cysticercus cellulose as 
described by me in a paper in the ‘ Philosophical Transac- 
tions’ of 1857. These organs bemg composed of a very 
highly refractile material, dissimilar in appearance to the 
adjacent structures, can easily be distinguished in very 
minute quantities; and these having a spherical figure, 
admit of being traced through all the changes of form 
attending the coalescence of the first visible particles, 
up to that of the recognisable parts of a hooklet. The 
following is the description of the development of these 
