238 MANUAL OF HISTOLOGY. 



place in the same manner as has been described above for the normal 

 structure. But that many subordinate peculiarities may make themselves 

 evident here must be granted. 



REMARKS. We should be obliged to overstep the bounds of a work of this kind 

 by a great deal did we enter more minutely, or in a manner which could be regarded 

 to any extent as exhaustive, upon this still unsettled question as to the origin of 

 connective-tissue. In the year 1839, its mode of origin was held by Schwann to be 

 the following : Cells, originally spheroidal, took on the fusiform figure, and, becoming 

 further elongated, underwent a splitting up of their substance into fibrillse, com- 

 mencing at their extremities, thus giving rise on the metamorphosis of the latter 

 into the so-called bundles of connective-tissue. As to the destiny of the nuclei of 

 these formative cells, it remained unexplained, and the development of elastic fibres 

 from other cells was looked upon as probable. Henle, however, appeared soon after 

 as propounder of a new theory of origin, in consequence of renewed investigation. 

 According to his view, connective-tissue consists of an originally nucleated blastema, 

 in which the nuclei are arranged with regularity, and the ground substance splits up 

 into bands following their direction. By a fibrillar metamorphosis of the latter, the 

 ordinary fasciculi are produced. At the same time, the nuclei are supposed to become 

 elongated into fusiform bodies, which may subsequently unite, forming fine elastic 

 fibres (Kernfasern). No personal investigations have been published by him as to 

 the formation of the larger elastic filaments. In 1845, Reichert brought out a very 

 important work for the history of connective-substance. In this he taught that between 

 the original cells of embryonic connective-tissue an intercellular matter gradually 

 makes its appearance, the former coalescing with this to form a homogeneous mass, 

 so that in that the nuclei are still recognisable ; we have arrived at about the same 

 starting-point as that maintained by Henle. Later on, the nuclei were supposed by 

 him to disappear in part, while the occurrence of fusiform cells was denied, and the 

 objects which had been held to be such, were declared to be (together with the fibrillse 

 of connective-tissue) artificial products, as already mentioned. Elastic fibres were 

 regarded as transformations of the ground substance. In the year 1851, however, 

 there came a turning-point, through the works of Virchow and Danders. These 

 investigators demonstrated, with the scanty aids to research of the time, in the first 

 place, the persistence of nucleated cells, and laid, with perfect justice, the chief stress 

 on these elements of the tissue. They fell, however, into a dangerous error in regard 

 to the origin of elastic fibres, in that they supposed the latter to take their origin 

 i'rom a change in these cells. According to both observers, the latter never take the 

 form of connective-tissue bundles, but enter into the construction of stellate and 

 fusiform corpuscles, which may unite to form elastic tubes and fibres. The latter, as 

 a rule, have origin only from such cells (a point long defended by Koellikcr). True 

 connective-tissue is intercellular substance. This view, supported by Virchow and 

 Donders, was at once attacked by Henle in the most determined manner ; the stellate 

 cells were declared to be the transverse sections of interstices between the bundles of 

 connective-tissue, and the whole to be an optical illusion. Now, although Henle, we 

 must confess, has in many respects gone too far, still he is entitled to praise for 

 having directed attention to errors in the theory just mentioned as that of Virchow 

 and Donders. On the other hand, this new theory, sometimes unchanged, and some- 

 times with greater or less modification, was received (and further developed by 

 observation of the normal as well as diseased tissues) by a number of new adherents of 

 the two men just named. The formation of bundles of connective-tissue from cells, 

 in the sense in which Schwann spoke of it, has only been supported (among men of 

 any note) by Koelliker, up to the year 1861, when he too gave it up ; all others 

 have regarded the fasciculi and fibrillse as metamorphosed intercellular substance. 

 Again, a new era was initiated by a paper by M. Schultze in Reichert and Du Bois- 

 Jtcymond's Archiv. 1861, p. 13. In this he proclaimed the formative cell of connec- 

 tive-tissue to be membraneless, like other young cells. 







10. The Tissue of Bone. 



140. 



Bony or osseous tissue is a member of the group of ' connective- 

 substances, by no means springing in the first instance and immediately 

 trom the cells of the middle germinal plate. It is rather formed 



