88 GENERAL ANATOMY OF THE TISSUES. 



A second and much more important point in which I differ from 

 Donders and Virchow is the general mode of looking at the connective 

 tissue. Both these writers hold that it is not composed of cells, but is 

 developed by the fibrillation of a homogeneous cytoblastema ; and they 

 believe that all the fusiform embryonic cells, which since Schwann's 

 time have been regarded as its formative cells, belong not to it, but to 

 the elastic tissue. I can by no means admit such a view, and it seems 

 to me to be comprehensible, only when we recollect that these authors 

 arrived at it more upon theoretical grounds, than by direct observation. 

 With Virchow, a passage in Schwann appears to have been conclusive, 

 where he describes the embryonic connective tissue as a gelatinous homo- 

 geneous mass, which dissolves upon boiling, and contains cells distri- 

 buted through it which are not affected by the boiling. Virchow does 

 not hesitate to extend this to all connective tissue, and to assume that 

 the substance soluble in water answers to the subsequently fibrous con- 

 nective tissue, while the insoluble cells are the formative cells of the so- 

 called nucleus-fibres. Here, however, he has omitted to notice that 

 Schwann speaks only of a determinate form of tissue, the lax or areolated, 

 and describes in a totally different manner the formation of the more 

 solid connective tissue, e. g. of a tendon. In this case we find, in direct 

 contrast to the former, no trace of cytoblastema, which can in no way 

 be directly observed, the tendon consisting throughout of fibre-cells, 

 either isolated or united into bundles of connective tissue. 



To observe this, however, the examination must be made at a very 

 early period, since, as Schwann has justly remarked, the elements of 

 the fibrous tissue are very early developed ; a circumstance from ne- 

 glecting to observe which, it seems that Donders has been led to adopt 

 the same view as Virchow. For my own part I have found Schwann's 

 statements confirmed in all essential points, with the single exception 

 that he was unacquainted with the formative cells of the elastic fibres, 

 and confounds them with those of the connective tissue. My observa- 

 tions upon these points are to be found in the following section. Hence 

 I cannot admit that cartilage and connective tissue are nearly allied, 

 inasmuch as the fundamental substances of both, even if chemically 

 agreeing, yet, genetically, are very different. 



Literature. A. Eulenberg, "de tela elastica," 1836; Virchow, "die 

 Identitat von Knochen, Knorpel und Bindegewebskb'rperchen, sowie 

 ueber Schleimgewebe," in the "Verhandlungen der Phys. Med. Gesell- 

 schaft in Wurzburg," Bd. II. 1851, p. 150; and " Weitere Beitrage 

 z. Kenntniss d. Structur der Gewebe der Bindesubstanz." Ebend. II. 

 p. 314 ; Donders in the " Nederlansch Lancet.," 1851, July and August; 

 and in the " Zeitschrift fur wissen. Zool.," Bd. III. p. 348 ; Kolliker, 

 " Ueber die Entwicklung der sogenannten Kernfasern, der elastichen 

 Fasern und des Bindegewebes;" in "Verb. d. Phys. Med. Ges. in 

 Wurzburg," Bd. III. H. 1. 



