Production of Transplantable Growth. 97 



II. The size of such a growth can be enlarged by a few 

 injections of a growth-promoting substance, i. e., tetheline, into the 

 protuberance itself. The growth treated with tetheline is three 

 times as big as its untreated neighbor. Sections show the implant, 

 bordering on the unchanged skin, closely connected with it by 

 newly formed tissue. The embryonic heart-muscle tissue par- 

 ticles are visible after 10 days. Newly formed connective tissue 

 penetrates into the subcutaneous connective tissue of the host. 

 The implant is vascularized by the blood vessels of the chicken. 

 In the skin above the implant, the previously described disarrange- 

 ment of the epidermal parts and the feather follicles has also taken 

 place. But though these growths often reach the size of a hazel- 

 nut, they are finally resorbed. 



III. The diet of the host, in which the prepared tissue particle 

 was going to be implanted, was now changed from mixed diet to 

 a vitamine-restricted diet. Chickens were fed with corn gluten 

 meal and the same implantation performed. Breasts of chickens 

 of the same age, but fed on different diet, showed a marked dif- 

 ference in the development of the breast muscles which are nearly 

 atrophied in chickens on vitamine-restricted diet. Protuberances 

 appeared after implantation in the same manner, as in birds fed 

 with mixed food. After twenty-four days half of a protuberance 

 was extracted and sectioned. The destruction processes in the skin 

 are nearly finished, all feather follicles are destroyed, and it could 

 be seen during the extraction that the tissue of the growth had 

 penetrated into the underlying tissue of the host. The remaining 

 half of the protuberance gradually disappeared and in its stead 

 a tumor-like growth appeared. It was partially extracted 

 eight weeks after the original implantation, the chicken dying 

 three days after this operation. Horizontal and transverse sec- 

 tions show the penetration of fibrous connective tissue into the 

 striped muscles, their compression and destruction, together with 

 compressed blood vessels and blood sinuses. Where these pro- 

 cesses are finished muscular tissue and fibrous connective tissue 

 of surprising structure appear. The hard tumor shows macro- 

 scopically deep pockets in which we see the destroyed blood 

 vessels and muscles; they seem to be filled with brown detritus. 

 Part of this original growth could be successfully grafted on 



