558 FCETAL 



lowing analytical* results : one hundred parts of the fluid contained six 

 teen parts of solid matter, which consisted of, 



Incipient fibrine, 



Albumen, 



Mucus, and muco-extractive matter, 



Muriate and phosphate of potass 



Phosphate of soda, 



Phosphoric acid, a trace. 



According to the researches of Mr. Simonf and Oesterlen the thymus is 

 composed of polygonal and mutually flattened membranous cells, measur- 

 ing from half a line to two lines in diameter and arranged in conical masses 

 around a central cavity. Each cell is surrounded by a capillary plexus 

 and connected to neighbouring cells by areolar tissue intermingled with 

 elastic fibres. The corpuscles found in the fluid of the thymus are dotted 

 nuclei measuring 3^3^ of an inch in diameter; and are subject to conver- 

 sion into nucleated cells and fat-cells. 



The Arteries of the thymus gland are derived from the internal mam- 

 mary, and from the superior and inferior thyroid. 



The Veins terminate in the left vena innominata, and some small branches 

 in the thyroid veins. 



The Nerves are very minute, and are derived chiefly, through the in- 

 ternal 'mammary plexus, from the superior thoracic ganglion of the sympa- 

 thetic. Sir Astley Cooper has also seen a branch from the junction of the 

 pneumogastric and sympathetic pass to the side of the gland. 



The Lymphatics terminate in the general union of the lymphatic vessels 

 at the junction of the internal jugular and subclavian veins. Sir Astley 

 Cooper has injected them only once in the human fffitus, but in the calf 

 he finds two large lymphatic ducts, which commence in the upper extre- 

 mities of the glands, and pass downwards, to terminate at the junction of 

 the jugular and subclavian vein at each side. These vessels he considers 

 to be the "absorbent ducts of the glands; l thymic ducts ;' they are the 

 carriers of the fluid from the thymus into the veins." 



Sir Astley Cooper concludes his anatomical description of this gland 

 with the following observations : 



"As the thymus secretes all the parts of the blood, viz. albumen, fibrine, 

 and particles, is it not probable that the gland is designed to prepare a 

 fluid well fitted for the foetal growth and nourishment from the blood of 

 the mother, before the birth of the fetus, and, consequently, before chyle 

 is formed from food? and this process continues for a short time after 

 birth, the quantity of fluid secreted from the thymus gradually declining as 

 &at of chylification becomes perfectly established." 



FCETAL LUNGS. 



The Lungs, previously to the act of inspiration, are dense and solid in 

 structure, and of a deep red colour. Their specific gravity is greater than 

 water, in which they sink to the bottom ; whereas lung which has respired 

 will float upon that fluid. The specific gravity is, however, no test of the 



* This analysis was conducted by Dr. Dowler of Richmond, 

 f "A Physiological Essay on the Thymus Gland," 4to. 1845. 



