THE OSSEOUS SYSTEM. 30 



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vessels. With respect to the other parts of the osseous system, the only- 

 question can be, as to whether the 2^<^^iosteiim and articular capsules 

 possess lymphatics. In the former, they have not yet been observed, 

 •whilst in the latter their existence has been asserted by several authors, 

 Cruveilhier, for example. It must be confessed, however, that it has 

 not been by any means proved that they arise in these structures, at all 

 events it appears to me to be very doubtful, whether the synovial mem- 

 branes themselves contain vessels of this kind, whilst it is perhaps certain 

 that lymphatics do exist in the loose connective tissue surrounding the 

 articular capsules, and between them and the periosteum of the apophy- 

 ses, particularly at the knee. 



§ 99. Nerves of the Osseous System. — The 'periosteum is abundantly 

 supplied with nerves, the majority of which, however, do not belong 

 properly to it, but to the bone {yid. infra). With respect to the proper 

 periosteal nerves, it appears that their number, on the whole, is not 

 considerable, so that even in some places they may be entirely absent, 

 as in the neck of the femur, and beneath certain muscles [glutceus 

 minimus, peroncei, &c.) ; but there are perhaps but few bones in which 

 they do not exist in one part or another. These nerves lie in the same 

 layer as the vessels, sometimes along the larger branches, sometimes by 

 themselves, arising, at all events in part, from the larger nerves of the 

 bone itself, and are manifestly distributed over considerable spaces, 

 although their ramifications and anastomoses are scanty. In the larger 

 trunks of these nerves the primitive fibres measure, most generally 0-002 

 —0-004 of a line, though their size gradually lessens, partly owing to 

 actual divisions, which I have seen with the utmost distinctness in the 

 periosteiun of the fossce infra-spinata, and iliaca in man, and J. N. 

 Czermtik in that of the frontal bone in the Dog ; and in part by a 

 gradual attenuation, to a diameter of 0-0012-0-0016 of a line, many, 

 and perhaps all, terminating with free extremities. On the articular 

 ends of many bones, such as those of the elbow, knee, and knuckle-joints, 

 I have noticed the nerves to be more abundant than elsewhere, ramify- 

 ing and anastomosing in the vascular connective tissue covering the 

 2)eriostemT], and following princip-ally the course of the blood-vessels ; 

 but in these situations, divisions and terminations of the primitive fibres 

 did not come under my observation. 



The nerves of the bone itself, which, with the exception perhaps of 

 the ossicula auditus and sesamoid bones, are universally present, do not 

 exhibit exactly the same conditions in all bones. In the larger ci/Iin- 

 drical bones, they penetrate, in company with the nutrient vessels, in 

 the form of one, or where two nutrient foramina exist, of two, pretty 

 considerable trunks (measuring as much as 0-16 of a line), visible to the 

 naked eye, directly into the medullary cavity, and are there distributed 



