. Anatomischer Anzeiger. Anatomy, Comparative; Anatomy, Comparative. 532 ments of the body, as my colleague Prof. W. H. Wilson, has demon- strated, and the hippocampus by means of the fornix is brought into more intimate relationship with the thalam- and mesencephalon than any other part of the "smell-brain". In the Mammalia, while the hippocampus maintains its important role, the pyriform lobe becomes especially well - developed, probably because it aÖ'ords the only path for smell-impressions to the neopallium, which now becomes the dominant organ of the nervous system. Let us now l
. Anatomischer Anzeiger. Anatomy, Comparative; Anatomy, Comparative. 532 ments of the body, as my colleague Prof. W. H. Wilson, has demon- strated, and the hippocampus by means of the fornix is brought into more intimate relationship with the thalam- and mesencephalon than any other part of the "smell-brain". In the Mammalia, while the hippocampus maintains its important role, the pyriform lobe becomes especially well - developed, probably because it aÖ'ords the only path for smell-impressions to the neopallium, which now becomes the dominant organ of the nervous system. Let us now leave these speculations and return to the examination of the corpus paraterminale. It has already been seen that the paraterminal body begins near the dorso-medial corner of the cerebral hemisphere, where the mesial edge of the hippocampus is situated, and extends downward to form part of the mesial wall (Fig. 1). It has also been shown that the tuberculum ol- factorium extends around the ventro-mesial corner to form part of the mesial surface. Where do these two constituent elements of the mesial wall meet — is it at 5 or at O (Fig. 1)? To decide this question and at the same time to establish the identity of the paraterminal body beyond all doubt let us study some more sections. I have chosen a series of coronal sections of a larval Lepidosiren of the same stage of develop- ment as those represented in Figures 9, 10 and 11, because the ventral bulging of the tuberculum olfactorium is not so extensive as it is in the adult: hence these sections are less unlike those of other verte-- brates than those of the adult. ^ Starting with the examination of Fig. 12, in which the formatio j bulbaris is seen as a cap on the dorsal aspect of the hemisphere, the whole mesial wall is obviously composed of paraterminal body. !. Fig. 12. Coronal section of a larval Lepidosiren (stage 38), passing through the olfactory bulbs, which form dorsal caps on the hemispheres. Series 140 A. Section
Size: 1530px × 1633px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublisherjenagfischer, books
