Detailed abstracts of papers on 1.- The morphological relations of the nervous systems in the annulose and vertebrate types of organization. 2.- The morphological constitution of the skeleton of the vertebrate head. 3.- The morphological constitution of limbs : communicated to the Cheltenham meeting of the British Association, August 1856 / by Professor Goodsir.

John Goodsir

Date:: [1857]

Credit: Detailed abstracts of papers on 1.- The morphological relations of the nervous systems in the annulose and vertebrate types of organization. 2.- The morphological constitution of the skeleton of the vertebrate head. 3.- The morphological constitution of limbs : communicated to the Cheltenham meeting of the British Association, August 1856 / by Professor Goodsir. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

58/72 (page 170)

first place, it may be questioned whether the corda dorsalis of the Fish reaches the region of the pre sphenoid ; and, in the second place, if I am correct in my determination of the ])ost-sphenoidal and temporal neurapophyses of the Fish, the two ascending limbs of this bone abut against these latter elements, and are not atall connected with the pre-sphe- noidal neurapophyses. As, moreover, these ascending limbs of the bone in question are more intimately connected with the bones which Pro- fessor Owen considers to be the ali-sphenoids, but which I must hold to be the inferior temporal neurapophyses, I am inclined to conceive it an ossified portion of the temporal centrum. With regard to the bone termed by Hallman os innominatum, which is small but well marked in the carp, and larger in the perch, and which Professor Owen considers to be the petrosal, I quite agree witli him. But while I do so, I make a distinction between an ossified portion of the auditory capsule and the bone whicli constitutes the corresponding neura- pophysis, in the same manner as I find myself compelled to admit the independent existence of the ethmoidal neurapophysis and the olfactory capsules, whether fibrous, cartilaginous, or osseous, and the corresponding independent existence of the variously modified sclerotics and the orbito- sphenoids. Proceeding now to the examination of the remaining elements of the post-stomal neural arches in the Fish, I would observe that if we put aside those conceptions of the constitution of the arches in question, de- rived from previous study of the cranium of the Mammal, the constitution of the corresponding arches in the Fish, which naturally suggests itself, is the following:— 1. Over the occipital centrum, the lateral occipitals and the external occipitals—as two pairs of neurapophyses ; and the superior occipital—as a single meta-neurapophyses. 2. Over the position of the temporal centrum, the bones termed petro- sals by the continental anatomists, but by Professor Owen petrosals in the cod, and ali-sphenoids in the carp, and over these the mastoids, these petrosals or ali-sphenoids, along with the mastoids—as two pairs of neurapophysis; and the contiguous or separated bones usually termed parietals, as a divided meta-neurapophysis. 3. Over the great basi-sphenoid, the bones termed by Professor Owen or- bito-sphenoids in the carp, and ali-sphenoids in the cod, with the post-fron- tals—as two pairs of neurapophyses, the meta-neurapopliyses being absent. Before making any statements in support of this view of the constitu- tion of the post-stomal neural arches iu the cranium of the osseous Fish, 1 would direct attention to the corresponding parts in the other Vertebrata, from the same point of view. In the Bird the occipital neural arch wants the ex-occipitals. The tem- poral arch possesses no centrum, but the petrosals, mastoids, and parietals, are placed one over the other as two pairs of neurapoph^'ses and a divided meta-neurapophysis. The post-sphenoidal centrum is surmounted by the post-sphenoidal wingS and the feebly-developed post-frontals—as two pairs of neurapophyses; while the meta-neurapophysis is deficient. In the Crocodiles, the occipital arch, as in the 13irds, has lost the upper pair of neurapophyses. The temporal centrum is not developed, but the two pairs of neurapophyses, and an undivided meta-neurapophyses—the petrosals (ali-sphenoids of Owen), mastoids, and so-called parietal—form a continuous arch. The post-sphenoidal centrum is again found to carry two pairs of neurapophyses, the great sphenoidal wings (orbito-sphenoids of Owen), and the post-frontals. The meta-neurapophysis is missing. In the Chelonians, the occipital arch consists of one pair of neurapo- physes and a meta-neurapophysis surmounting a centrum. The tern-

Licence and re-use

Contents