An atlas of the medulla and midbrain / Edited by H.McE.K.

  • Florence R. Sabin
Date:
1901
Catalogue details

Licence: In copyright

Credit: An atlas of the medulla and midbrain / Edited by H.McE.K. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    MlCUl'LLA UliLOiMiATA, I'O.X.S AM) .MIDIIIJAIN made, esi>ecially from the ends of the sctioiis, iuid the median plane was kept true, liy this comparison a wax pUite could be held in ])ro|)('r pdsitiuu with reference to the hoard; it was then easy, on iioidiiig' the phite a little higher, to sight through the space made by the removal of the bundle representing the medial lemniscus and adjust the piece of wax corresponding to it into j)lace below. The position of each piece was checked also by measurements from various points on the sections. In this preliminaiy reconstruction, which may well be called the foundation of the model, the trapezoid body was included, inasmuch as it forms a cross-bar and, therefore, gave many points for control measurements. Before fusing the pieces of this foundation, I used as a further check upon the piling the external form of the inferior olive, which is so complex that its pai-ts must be piled accurately in order to fit at all. Moreover, since the olive makes a definite curve on the sur- face of the medulla oblongata, the shells left after cutting out the niicleus Avere piled Avith reference to this cui've; the nucleus in turn was piled by measurements from the shells. The olive thus modeled was placed in position with reference to the medial lem- niscus, and it Avas found that measurements taken from A-arious points on the oliA^e to the lemniscus agreed Avith the corresponding measurements on the sections. This confirmed the conviction that the latter had been piled correctly. A further check of the accu- racy of the Avork was found by comjjaring the dorsal border of the lemniscus in the model Avith the same border, as seen in a sagittal section of the medulla oblongata. Having made sure of the accu- racy of the piling of the foundation, its parts were fused by means of a hot iron, strengthened by buried Avires and fastened securely to the pedestal. With the help of this foundation, all the structures of the model Avere piled. Each bundle Avas taken up separately, its ^ifirts cut from the plates, piled and fused into a unit. At the end, the entire model Avas found to fit, Avhicli Avas a further test of the accu- racy of the Avork. The value of such a model lies in its illustration of spatial rela- tions and the suggestions Avhich these giA'e Avith regard to the course of the development. Tt is necessary to point out certain limita- tions of the method. First, in making the model, fibres Avere grouped together according to their function. The bundles thus