HETEROTAXICS include those forms which show transposition of the internal viscera. either of the thorax or of the abdomen. Rarely we find only a single organ transposed; often all are in an abnormal position, hut this change is aeeom panied by no interference. of nutrition nor of function.. So at times the heart will be found on the right side or the liver on the left, and yet the individual is unconscious of any irregu larity.
lIERMAPHRODITICS. Ahlfeld defines a true her maphrodite as an individual possessing func tionally active glands of both sexes, with ex creting ducts and external genitals, so that the (Alves of both sexes can he fulfilled. Indisputable evidence of such a case has not been addueed, al though there are numerous instances where glands presenting the histological characteristics of both sexes have been present in one person. False hermaphrodites present typical glands of one sex and others of a more or less mixed or modified type. They are usually masculine in sex. There are all degrees of obnormality in development, from a. $light, enlargement of the resicula prostatica (the masculine .uterus of \Veber), without any alteration in the external genitals. to a fully developed uterus with tubes and vagina complete in a male subject. The penis in these eases is rudimentary, and a condi tion of hypospadias (a malformation of the penis. in which the orifice of the urethra is under neath or behind the glands) exists. The scrotum is ill developed, and the testicles remain in tho abdomen. The absence of ovaries is not detected, so that the mistake in sex may naturally per sist. until a post-mortem examination reveals their absence and the true sexual nature of the individual is apparent. See HERMAPHRODITE.
In this elass we will first consider autositie single monsters which are ca pable of independent existence in the w(nnb, and are the result of an arrest in development. of fusion, or' of displacement. of important parts. (1) Ertroin Cl us .—Tbk group includes aborted or imperfectly formed extremities which present various dgrees of shortening or else are entirely absent. Some eases show rudimentary limbs,
hut perfectly formed hands and feet whieh ap pear to come immediately from the trunk. (2) yin in el as.—The Ilelvis and lower extremities in the individuals of this group a n• imperfectly developed, and the two lower limbs are more or less fused. Sometimes this fusion is complete and the feet are wholly lacking. (3) ('e/ostoma. —The individuals in this class show a varying degree of cleft in the walls of the abdomen or of the thorax. and consequent eventration. Ano malies of the intestinal tracts and of the urinary and genital apparatus are frequent aecompani meats. Malformations of the head are classified under the next three groups—(4) exCscepha1us, (51 psendeniephalis. and (ti) aicncepbalus. In group It) a malformed brain exists. situated in part at least within a cranial cavity of which the walls are imperfect. In group (5) the cranium is even more rudimentary and the brain tissue is but poorly represented, while in the itnencephalus the true nerve elements are wholly lacking in the mass of tissue lying within the shallow and imperfect cranial cavity. These Brainless monsters are almost always feminine. In (7) the c•ycloeepbali the eyes approach the mid line and more or less closely unite. These organs are poorly developed or rudimentary, and the nose is atrophied, although in certain in stances a. hypertrophied proboscis may arise from above the fused sockets. The lower jaw is poorly developed or wanting in (8) the oetocepu plie, and the ears approach each other and fre quently become fused below. The mouth is of course distorted to an exceptional degree.
onliphalositie single are embryos de pendent on other embryos within the womb for their own imperfect development. The primary f(etus is usually well formed, and supplies both itself and the with blood by means of all extensive anastomosis of placental and um bilical vessels.