SECT. 5, 6.] SIMPLE ELEMENTARY PARTS. 9 



simple ones, and which are most fitly designated higher elementary 

 parts. Such a coalescence has, hitherto, been observed only in 

 cells with certainty, and many of the tubular and fibrous ele- 

 ments of the body proceed from it. 



§ 5. Fluid and solid intermediate Substances. — Whilst in plants 

 the elementary parts, in most cases, are directly united with 

 each other, a special fluid, pulpy, or solid intermediate sub- 

 stance is very widely distributed in animals, which is often sub- 

 servient to quite specific purposes, as the blood and the juices of 

 glands, and is always ultimately derived from the blood, and 

 more closely or more remotely related to it. When such 

 an intermediate substance participates in the formation of the 

 elementary parts, it may be called formative fluid, cytoblastema, 

 Schleiden (from kvtos vesicle, and fiXacrTi'-yia germinal material), if 

 it be present for the maintenance of them, it is denominated nutri- 

 tive fluid ; when, lastly, it has nothing to do either with the one or 

 the other, it is designated fundamental or connective substance. 

 The cytoblastema is usually perfectly fluid, as in the blood, chyle, 

 many juices and glands, the contents of glandular follicles, and in 

 many embryonic organs; more rarely mucoid and viscid, as in the 

 gelatinous areolar tissues of embryos (see infra). The nutritive 

 fluid occupies, in fully developed organs, the place of the formative 

 fluid ; and, except where it is contained in special canals and spaces, 

 as in bones, teeth, and in many organs composed of connective 

 tissue, is present in such a small quantity that it cannot be directly 

 observed. A fundamental substance, lastly, occurs in the cartilages, 

 and in the bones forming from these, also in the teeth, as a 

 firm, or even bony, hard, homogeneous, granular, or even fibrous, 

 connective mass of cellular elements, which arises partly as a secre-. 

 tion of the latter, partly from the blood independently of them. 



The occurrence of a solid, fundamental substance, directly deposited from 

 the blood, shows that all the solid parts of the body are not, without excep- 

 tion, formed from cells or in dependence upon them, as Schwann was disposed 

 to assume. It is likewise certain, that in pathological formations such masses 

 occur very extensively, the fibrinous exudations, especially, being capable of 

 becoming transformed into permanent parts or tissues, without preliminary 

 organisation, i.e. formation of cells. 



A.— SIMPLE ELEMENTARY PARTS. 



1. — Crystals, Granules, Filaments, Vesicles, Nuclei. 



§ 6. When the simple elementary parts are compared with one 

 another, there results an entire series of forms. The most simple of 



