The anatomical record . eral has caught up with the excessive growth of the noto-chord. Anteriorly the notochord has lost contact with Rathkespocket, ending in a hooked formation near it. Contact withRathkes pocket is lost usually at any time between the ages 13to 18 mm. The of the forebrain is evaginated to form theinfundil)ular process. The roof of the i)harynx just at the opening into the esophagusis invaginated to form a distinct pharyngeal pocket, the base of rHAKYVliKAl, I\ TIIK PKI KMFiKVO 475 which is in closo contact with the unla^o of the esophageal nms-culatiire,
The anatomical record . eral has caught up with the excessive growth of the noto-chord. Anteriorly the notochord has lost contact with Rathkespocket, ending in a hooked formation near it. Contact withRathkes pocket is lost usually at any time between the ages 13to 18 mm. The of the forebrain is evaginated to form theinfundil)ular process. The roof of the i)harynx just at the opening into the esophagusis invaginated to form a distinct pharyngeal pocket, the base of rHAKYVliKAl, I\ TIIK PKI KMFiKVO 475 which is in closo contact with the unla^o of the esophageal nms-culatiire, which we liavo noted hcforc (^fi^s. 4,.)). It is importantthat this pociiit be clearly distinguished from the hursa shown infigures 4 and 5, the position of which was ce|)halad as indicatedby the letter x. This pocket appears regularly after 13 is constant in occurrence. It is possible that it arises pri-marily from the tension exerted on the pharyngeal wall at thisregion by the developing esophageal Kig. 7 Iig embryo III F, Cornell Collection, 17 miu. Ueconstruction of raid-plane sagittal section of pharyngeal region. Notochord black. X 15. Pig embryo 17 mm. in length. Fig. 7. This embryo shows the notochord extending through the to come in contact tliree times with the pharyngeal epithe-lium. These are probably persistences of such secondary con-tacts as are shown in figUFc 5. The condition is by no meansuncommon, three of the ten eml)ryos examineil ranging in lengthfrom i;^ to 17 nmi. having shown similar contacts. The epi-thelium at these points of contact is thickened slightly l)ut notat all evaginated. .Vnteriorly the notochord ends in a sharp,double twist within the basilar plate. Uathkes |)ocket has be-come constricted off from the pharynx, and Sessels pocket hasdisappeared. The condensation of mesenchyme indicating the 476 iMTii m\i) ptTidiondriinu of the basilar i)liit(> iuid the doveloi^ing fasciapharvnp;-l):isilaris has lost con
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectanatomy, bookyear1906
