BECT. 103.] OSSEOUS SYSTEM. I 93 



by a single, moderately-thick line, a thicker coat, which presents 

 delicate indentations npon its inner side. When this has attained 

 only 0001'" in thickness, it may already he perceived that the 

 cavities of the cartilage-capsules are in the act of being trans- 

 formed into lacunas; and this process becomes still more distinct 

 farther within the bone. The thickness of the membrane in 

 question, together with the diminution of its cavity, is seen to in- 

 crease more and more, the indentations of its inner boundary line 

 become more pronounced, and, contemporaneously with these 

 changes, the walls become darker and darker, from the depo- 

 sition of calcareous matter. The slow ossification of the matrix 

 between the capsules very much facilitates the observation of all 

 these changes, and permits not only the first metamorphoses of the 

 cartilage-capsules to be very narrowly investigated, but also their 

 subsequent conditions, at a time when they must be called bone- 

 capsules and lacunas. To this circumstance alone is to be ascribed 

 the establishment of the interesting fact, that cartilage- capsules 

 which enclose secondary cells pass, in their totality, into a single 

 compound bone-capsule. Very frequently such bone-capsules are 

 found with two cavities, which, according to the degree of their 

 development, are sometimes wide and furnished .with short pro- 

 cesses, sometimes present narrow cavities and. wnger canaliculi, 

 and resemble completely the fully-developed lacunas. Compound 

 capsules, with three, four, and five cavities, are more rare, still they 

 also occur here and there in almost every preparation. In all 

 these cartilage-capsules, and in the bone-capsules originating from 

 them, there are not only, as I formerly believed, the remains of 

 the original cell-contents together with the cell-nuclei, but also the 

 original cartilage-cells, or primordial utricle, only it is smaller. 

 , Since, in perfectly fresh objects, it accurately fills the cavity of the 

 cartilage-capsule, it will, perhaps from the beginning, project by 

 means of delicate processes into the pore-canals of the thickened 

 capsule, still I have not yet succeeded in observing them as stel- 

 lated bodies in the earlier stages of development; while, on the 

 other hand, this is extremely easv in the latter, by macerating: 

 them in hydrochloric acid. When the cartilage-capsules have, in 

 the manner above stated, passed into distinct bone-capsules, con- 

 taining delicate cells and other contents, but lying free in the 

 unossified matrix, the final alterations take place, in consequence 

 of which the ricketty bone-substance assumes pretty nearly the 

 nature of the healthy tissue. These changes chiefly consist : first, 

 in the matrix beginning to ossify, and without primitive calcareous 



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