INCREASE IN SIZE AND WEIGHT IN THE PROCESS OF GROWTH. 455 



by suture to the freshened margins of the deficiency, the pedicle being divided 

 only after the approximated margins have united firmly. In this way, a new 

 cutaneous covering for the nose can be formed from the skin of the back from 

 another person, or from the skin of the patient's own arm, or from the skin of 

 the forehead. It is possible also to transplant even large, entirely detached flaps 

 of skin, without a pedicle, even after they have been preserved for fifty hours 

 in 0.6 per cent, sodium-chlorid solution at room-temperature. 



To form a cutaneous covering for large granulating (previously carefully 

 cleansed) ulcerous surfaces Reverdin and Thiersch apply under pressure numer- 

 ous rapidly detached bits of cutis the size of beans upon the granulations, or 

 after removal of the latter upon the freshened wound-surface, where they become 

 adherent. From the margins of these fragments newly formed layers of epidermis 

 extend over the entire surface of the ulcer. Enderlin was able to employ 

 successfully such fragments after preservation for four days moistened with 

 physiological salt-solution. The excised spur of the cock can be made to grow 

 upon the comb. Bert transplanted the denuded tails and feet of rats beneath 

 the skin of the back of other rats. The transplanted parts became adherent and 

 formed vascular communications with adjacent tissues, and even their bony parts 

 increased in size. Parts excised as long as three days previously exhibited similar 

 phenomena. Detached portions of periosteum transplanted to other situations 

 likewise heal in place and even develop bone. Extracted teeth may be replaced 

 and even in a second person, v. Hippel transplanted successfully a piece of a 

 rabbit's cornea 4 mm. square in a defect in a human eye, the clear membrane 

 of Descemet being preserved as a foundation, but the transplanted structure sub- 

 sequently became turbid. Also blood and lymph can be transfused. 



All of the transplantations mentioned succeed almost solely between 

 individuals of the same species. Most tissues, however, are not susceptible of 

 transplantation, for example muscles, nerves, glands and organs of special sense. 

 In the lower animals, even entire parts can be transplanted; for example two 

 pieces of different earthworms may unite, and also of hydra. 



The union of two higher animals (rats and others) was successfully effected 

 first by Bert in 1862, who divided the skin of the trunk and united the margins 

 of the wounds in the respective animals by suture. Union had taken place in 

 the course of five days. When atropin was administered to one of the animals 

 the pupils of both dilated. Post-mortem injection demonstrated the exist- 

 ence of anastomoses between the vessels of both. That such union may take 

 place also in man is shown by the experiments related on p. 454. The procedure 

 might be of therapeutic significance, as the possibility does not appear excluded 

 that the union of the skin, for example along the extensor aspect of the two fore- 

 arms, might result in an influence of the one individual upon the other, whether 

 to the end of conveying nutritive juices, or for the removal of certain substances 

 from the body of the one (as for example in case of insufficiency on the part of 

 certain excretory organs), or for the transmission of antitoxins and the like. 



INCREASE IN SIZE AND IN WEIGHT IN THE PROCESS OF 



GROWTH. 



In the first period after birth the length of the body, which on the average 

 is - 1 of that of an adult, exhibits the most rapid increase; in the first year about 

 20 cm., in the second 10 cm. more, in the third about 7 cm.; from the fifth to 

 the sixteenth year the annual increase (about 5^ cm.) is pretty much the same. 

 From the twentieth year on, only slight growth takes place. From the fiftieth 

 year on, the size of the body diminishes, principally in consequence of attenuation 

 of the intervertebral discs. The reduction may reach 6 or 7 cm. up to the eightieth 

 year. 



The weight of the body (about ^ of tnat of the adult) diminishes constantly 

 in the first five days or week after birth in consequence of evacuation of meconium 

 and of the small amount of food taken at first, together with increased functional 

 activity (generation of heat, respiration, digestive activity), as a result of which 

 the metabolic products are considerably augmented. Not before the tenth day 

 does the weight of the child again equal that of the newborn. Later on, the 

 increase in weight exceeds that of the increase in length of the body during corre- 

 sponding periods. In the first year the weight is trebled. In man, the maximum 

 is reached at about the fortieth vear. At about the sixtieth year reduction in 



