40 GENERAL ANATOMY OF THE TISSUES. 



such a manner that they lose their independence and cease to exist as 

 isolated elements. In this manner compound forms arise, each of which 

 answers genetically to a whole series of simple ones, and which may 

 most fittingly be called the " higher elementary parts." Such a coa- 

 lescence has been observed with certainty only in cells, and from these 

 most of the tubular and fibrous elements of the body are produced. 



5. Formative and Nutritive Fluid Interstitial substance or matrix. 

 While in plants the elementary parts in by far the majority of cases, 

 unite directly with one another, in animals there is a very wide differ- 

 ence ; a peculiar interstitial substance which combines them, and is ulti- 

 mately derived from the blood, is always in a lower or more distant rela- 

 tion therewith. If this take a direct share in the formation of the elemen- 

 tary parts it is called " formative fluid," CytoUastema (Schleiden), from 

 xt/fas, a vesicle, and /S^O-T^^ germ substance ; if it be present for their 

 maintenance, it is called "nutritive fluid;" if it have nothing to do 

 with either the one or the other of these functions, it is called the " ma- 

 trix" or connecting substance. The cytoblastema is usually quite fluid, 

 as in the blood, in the chyle, in many glandular secretions, in the con- 

 tents of the glandular follicles, and in many embryonic organs; more 

 rarely, viscid and like mucus, as in the gelatinous cellular tissue of 

 embryos (vide infra), still more rarely solid, as the blastema from which 

 the villi of the chorion arise and grow. The " nutritive fluid" takes 

 the place of the formative fluid in all perfect organs ; and except when 

 it is contained in special canals and cavities, as in bones, teeth, and 

 perhaps in some cellular organs, is present in so small a quantity, that 

 it cannot be directly observed. A matrix, lastly, is found in cartilages 

 and bones as a solid, homogeneous, granular, or even fibrous substance 

 connecting the cellular elements and for the most part arising from the 

 blood, independently of them. 



The occurrence of a solid blastema, growing independently, in the 

 villi of the chorion and of a solid matrix deposited directly out of the 

 blood demonstrates that all parts of the body are not, as Schwann was 

 disposed to believe, without exception developed from cells or in depen- 

 dence upon cells. A few more recent authors, as Reichert, Donders, 

 and Virchow, also consider that the connective tissue, excepting its elas- 

 tic element, is to be reckoned among those tissues which are not at all, 

 or not wholly, derived from cells ; but, as we shall see below, incorrectly. 

 On the other hand, it is certain that in pathological formations such 

 masses very frequently occur, fibrinous exudations becoming changed in 

 great measure, without previous organization, i. e. cell formation into 

 permanent tissues.* 



[* The Enamel and the Dentine of the teeth, and the so-called Cuticle of the hair (see 

 'O.i Hair and Teeth, and ' Quarterly Journal of Microscopical Science' for April, 1853), must 



