A Reference handbook of the medical sciences embracing the entire range of scientific and practical medicine and allied science . has become U-shaped, though the left arm is muchlonger than the right (Fig. 5244). Its outline is quiteirregular. In this the trans\erse part of the U whichruns across the middle line has sunk to the level of thefourth visceral pouch. This part shows the usual net-work structure formed by cords of solid cells. The armsare crescentic in cross section, with the hollow lookingaway from the middle line and embracing tlie thymus,although the two do not come in contact. T
A Reference handbook of the medical sciences embracing the entire range of scientific and practical medicine and allied science . has become U-shaped, though the left arm is muchlonger than the right (Fig. 5244). Its outline is quiteirregular. In this the trans\erse part of the U whichruns across the middle line has sunk to the level of thefourth visceral pouch. This part shows the usual net-work structure formed by cords of solid cells. The armsare crescentic in cross section, with the hollow lookingaway from the middle line and embracing tlie thymus,although the two do not come in contact. The lateralthyroid rudiments, which consist of hollow tubes sur-mounted by solid expansions, are still connected with the 573 Tick Fever. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. I pliaryiix. Tlie two sides are imsynimetrieal. Ou theright side the ventral knob is smaller tliau the dorsal,while on the left they are about equal in size and placedon the same level. In an embryo only sliglitly older tlie median tliyroid isstill U-shaped, though the right arm is still smaller than ,, VP.()--. l^ ^«(Thjtl} FIG. 5244.—Ventral View of the Pharvnx of an Embryo Five WeeksOlil (No. 109). ( in the last and not so long as the one on the left latei-al rudiments show in this embryo the greatestlack of symmetry of any of those studied by Sudler (). The right rudiment is still connected with thepharynx by a small hollow stalk, while on the left sidethis couneeliou has entirely disappeared. On the rightside the ventral knob touches the middle of the right armof the median rudiment, but there is no histological con-tinuity, whereas on the left .side the ventral knob not onlytouches the median rudiment, but there is actual conti-nuity. As in the embryo described before, the ventralknob on the right side is much smaller than the dorsalone, while on the left side tliey are of almost the same median and lateral thyro
Size: 1941px × 1288px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorbuckalberthalberthenr, bookcentury1900, bookdecade1900
