A manual of midwifery / by Alfred Meadows.

  • Alfred Meadows
Date:
1876
Catalogue details

Licence: Public Domain Mark

Credit: A manual of midwifery / by Alfred Meadows. Source: Wellcome Collection.

    74/528 (page 46)
    40 membranes of the brain are formed at about the sixth or seventh week, the arachnoid rather later. They are developed from the primary encephalic mass. Having now given the chief features connected with the development of the internal organs of the fcetus, it may be worth while to notice some of the more obvious external characters by which the age of a foetus may at a given time be distinguished; only those well authen- ticated will be noticed, and such as the average presents. Fuller details may be seen in Devergie's Medecine Legale. At the end of the first month, the body is elongated, straight, attached at its lower extremity by a very short cord to the membranes, concave in front, convex behind; head but slightly distinguishable; no appearance of ex- tremities ; bladder and liver very large : the mouth repre- sented by a cleft; the eyes shown very faintly by two dark spots; average length about half an inch; whole surface of chorion, villous. During the second month, the body is curved; head very large, but the neck scarcely denned; face with its openings perceptible; extremities quite distinct, the upper usually appearing first near the head, and at about the fifth week ; the lower near the anus; umbilical vesicle, the size of a large pea, situate close to the abdominal wall, but external to the amnion ; umbilical cord distinct, and composed of omphalo-mesenteric vein and artery, two umbilical arteries and vein, the iirachus, and duct leading from the umbilical vesicle to the intestine, which is said afterwards to constitute the vermiform appendage; the heart and genitals visible; average length at the end of second month about 1| inches; chorion distinct from amnion, formation of placenta commencing. At, the end of three months, extremities divided into their separate parts ; fingers and toes webbed; genitals quite distinct; lungs, thymus, spleen, supra-renal cap- sules, and kidneys distinct, the latter lobulated; cerebro- spinal axis divisible into its leading parts, and nervous structure apparent, though its consistence is very soft; ventricles of the heart separate; eyelids joined together, pupillary membrane visible; mouth and anus closed ; nose and ears present; insertion of the cord removing from the pubis higher up the abdomen, this it continues to do during the rest of intra-uterine life: average length about 2i inches. The two deciduae are in contact, the placenta