451 
nate Histo-plasts, or Histo-plastic Germs, and I conceive 
them to be of three kinds, Granules, Fibres, and Cells. The 
accompanying Table will exhibit more clearly my views of the 
order of precedence of the elementary parts of the organic 
fabric : 
AMORPHOUS ORGANIC FLUID. 
From which become developed— 
E, 
A-PLASTIC ELEMENTS. 
1. Primary Organic Granules : 
(a) Isolated ; 
(b) Aggregated ; and thus forming— 
. Granular Corpuscles; or, 
oo bb 
. Granular Stroma or Base. 
. Hyaline Membrane (Cell Membrane, &e.) 
. Hyaline Stroma or Base. 
. Hyaline Vesicles. 
an > 
IT. 
HISTO-PLASTS OR TRUE HISTO-PLASTIC GERMS. 
7. Plastic Corpuscles, Granules, Nucleoli, Nuclei, and other 
Germs, if any. 
8. Fibres (themselves formative elements). 
9. Cells. 
10. Definite Tissues. 
It is unnecessary here to go farther into the study of 
these individual elements, the forms of which must be familiar 
to all experienced microscopic observers ; to the class of hyaline 
structures evidently belongs the membrane alluded to by 
Schwann, and whose formation even he found it difficult to re- 
concile with the éxclusive adoption of his cell theory. He ob- 
serves in reference to it : “In many glands, as for instance the 
kidneys of a young mammalian foetus, the stratum of cells sur- 
rounding the cavity of the duct is enclosed by an exceedingly 
