_The second month._ Every part has now become much more developed, and the general form is that of a human being. The superior members are much more elongated, and the inferior ones begin to be distinguished, forming in the same manner as the others. The fingers are united together by a membrane, like the web on a Frog's foot. In the ribs, clavicles, and jaw bones, a few points can be seen ossified, the cartilage beginning; to harden into bone. The rudiments of the first teeth are also visible. The weight is about one drachm, and the length one inch. _At about seventy days_ the eyelids are visible, the nose becomes prominent, the mouth enlarges, and the external ear may be seen. The neck is well defined. The brain is soft and pulpy, and the heart is perfectly developed. Every organ is originally formed without either blood or blood vessels. The circulation which afterwards takes place in them is merely for their subsequent development. The heart is perfect in all its parts, and even has a slight motion, before the blood is found in it. _Three months._ All the essential parts are well defined. The eyelids distinct, but firmly closed. The lips perfect, but drawn tightly together. The heart beats forcibly, and in the larger vessels red blood is seen. The fingers and toes are defined, and the muscles begin to be apparent. The organs of generation are remarkably prominent, but still it is somewhat difficult, at first, to distinguish the sex by these organs, notwithstanding their development, as the principal parts in both are nearly identical in form. It can, however, be ascertained by other circumstances, as the form of the head, dorsal spine, thorax, and abdomen. It now weighs about two ounces and a half, and measures four or five inches in length. _Four months._ The development is remarkably increased. The brain and spinal marrow becomes firmer, the muscles distinct, and a little cellular tissue is formed. The abdomen is fully covered in and the intestines are no longer visible. A little of the substance called _meconium_ even collects in the intestines, the same as is found in at birth. It now weighs seven or eight ounces, and measures six or seven inches. The bones are ossified in a great part of their extent, and the rudiments of the second set of teeth are visible, under the first. The uterus now is so large that it can no longer remain in the lower part of the pelvis, but is compelled to rise up into the abdomen for more room. This change of position is improperly called _quickening_! Sometimes it takes place very gradually, so that it is scarcely noticed, but more frequently it rises suddenly, disturbing all the internal organs, and causing in them considerable derangement till they accommodate themselves to the change. This occurrence often causes unnecessary alarm, though the sickness, and other unpleasant sensations, are always sufficiently annoying.