. The American journal of anatomy. ndthe paraphysis. I believe that the firstprominent fold of choroid plexus in anadult chicken, behind the paraphysis, repre-sents morphologically the large, broad, well-developed velum transversum of the , as is represented in Fig. 1. There is almost no change in theappearance of the paraphysis. Its cavity is more constricted, but itswalls are of about the same thickness, and of course its position in thetwo plates is identical. Above and to the left of the paraphysis thereis a curious vesicle (Ve) which I am at a loss to explain, but will refert
. The American journal of anatomy. ndthe paraphysis. I believe that the firstprominent fold of choroid plexus in anadult chicken, behind the paraphysis, repre-sents morphologically the large, broad, well-developed velum transversum of the , as is represented in Fig. 1. There is almost no change in theappearance of the paraphysis. Its cavity is more constricted, but itswalls are of about the same thickness, and of course its position in thetwo plates is identical. Above and to the left of the paraphysis thereis a curious vesicle (Ve) which I am at a loss to explain, but will referto again farther on. Figs. 6 and 7 represent the same sections under different powers ofmagnification. It was desirable to draw this section with the samepower as was employed for the others, but the field was not largeenough to include the entire section and so it was tliouglit advisable tofirst study its topography with a lower power, without which it does notseem to me that it would be intelligible. The figures represent frontal. Fin. 5. Sajritta] section of a 10days chickens brain. X Franklin Dexter 19 sections which pass through the ^jaraphysis of a three-days chickensbrain. In Fig. G one is able to distinguish the narrow lateral ventricles,the slit-like cavity of the forebrain lying between the two optic thalami,a very minute paraphysis, and just above it a triangular cavity or ves-icle. This seems to be the same structure which we saw in sagittalsection (Fig. 5). On examination of Fig. 7 the same regions are much more easily dis-tinguished. Here the paraphysis is seen clearly to be a portion of theepithelial roof of the forebrain. Its cavity presents a very uniformappearance, but wdth a higher power, small fissures are observed run-ning off from it, and piercing its wall for variable distances. A large,transverse vessel separates it from the vesicle. The space between the
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectanatomy, bookyear1901
