12th week.)| two and | ounces. |separated; nails recognisable. The | a half | |sex can be detected by the aid of | inches. | |a lens. Suprarenal capsules and | | |thymus gland are formed. The | | |cavities of the heart and divisions | | |of the brain distinct. The placenta | | |isolated; the umbilical vesicle, | | |allantois, &c., have disappeared. ----------+----------+------------+---------------------------------- _Fourth_. | | | (End of | Five to | Two and |The skin rosy and tolerably dense. 16th week.)| six | a half |Sex seen without aid from lens. | inches. | to three |The mouth is large and open; the | | ounces. |umbilicus is near the pubes. | | |Meconium of a greyish-white | | |colour in the large intestines. ----------+----------+------------+---------------------------------- _Fifth_. | | | (End of | Ten to | Seven |From the fifth month the length of 20th week.)| eleven | to ten |the fœtus in inches is almost | inches. | ounces. |_exactly double the number of the | |varying in |lunar months_. The nails are | |individuals.|distinct. The head, liver, heart, | | |and kidneys are disproportionately | | |large. The hair appears as a light | | |down. The meconium is of a | | |yellowish-green colour. Points of | | |ossification, pubes and os calcis. ----------+----------+------------+---------------------------------- _Sixth_. | | | (End of |Twelve to | One to two |Down and sebaceous matter cover 24th week.)| thirteen | pounds. |the skin. The colour of the body | inches. | |is a cinnabar-red, and the | | |umbilicus is farther from the | | |pubes. The meconium is darker | | |in colour; and the scrotum is | | |empty, the testes being close | | |to the kidneys. The pupillary | | |membrane is still present. ----------+----------+------------+---------------------------------- _Seventh_. | | | (End of | Fourteen | Three or |The skin is of a dirty-red colour; 28th week.)|to fifteen|four pounds.|the hair about half an inch long,